Dissertations / Theses on the topic 'Wear resistant properties'

Abstract The effect of microstructure on the mechanical properties of thermomechanically rolled and direct quenched wear resistant steel plates was investigated. The prior austenite morphology and transformed microstructure was studied and compared to tensile properties, impact toughness, hardness and bendability. Also, the effect of inclusion structure and texture on the mechanical properties was investigated. Decreasing the finishing rolling temperature increased the level of austenite pancaking. Centerlines of samples consisted mainly of auto-tempered martensite. With lower finishing rolling temperatures and higher reductions in the non-recrystallization regime the formation of polygonal ferrite and bainite increased at the subsurface layers. Lowering the finishing rolling temperature increased the intensity of {554} texture component at the centerline and {112} shear texture component at the subsurface layers. The impact toughness and strength were observed to increase with increasing austenite pancaking in mostly martensitic specimens. High fraction of polygonal ferrite seemed to have a detrimental effect on strength and impact toughness. Impact toughness is also impaired by the presence of coarse inclusions. Homogeneous, mostly martensitic microstructure through thickness seemed to ensure good bendability. Inhomogeneous, highly ferritic microstructure or structure with an intense {112} shear texture component in the subsurface layers combined with elongated MA islands near the surface resulted in the highest minimum bending radiuses
Mikrorakenteen vaikutus kulutusterästen mekaanisiin ominaisuuksiin Tiivistelmä Työssä tutkittiin mikrorakenteen vaikutusta termomekaanisesti valssattujen ja suorasammutettujen kulutusteräslevyjen mekaanisiin ominaisuuksiin. Perinnäisen austeniitin morfologiaa sekä lopullista mikrorakennetta verrattiin vetokokeista, iskusitkeyskokeista, kovuusmittauksista ja särmäyskokeista saatuihin tuloksiin. Myös näytteiden sulkeumarakenteet sekä tekstuurit mitattiin, ja niitä verrattiin mekaanisiin ominaisuuksiin. Austeniitin litistymisen huomattiin lisääntyvän valssauksen lopetuslämpötilan laskiessa. Näytteiden keskilinjat koostuivat pääosin itsepäässeestä martensiitista. Matalammat valssauksen lopetuslämpötilat lisäsivät polygonaalisen ferriitin ja bainiitin muodostumista levyjen pintakerroksiin. Keskilinjojen {554}–tekstuurikomponentin, sekä pintakerrosten {112}–leikkaustekstuurin intensiteettien huomattiin kasvavan valssauksen lopetuslämpötilan laskiessa. Lujuus ja iskusitkeys paranivat austeniitin litistymisen lisääntyessä, kun rakenne oli pääosin martensiittinen. Kun näytteisiin muodostui runsaasti ferriittiiä, havaittiin iskusitkeyden ja lujuuden alenevan merkittävästi. Myös isokokoisten sulkeumien havaittiin olevan erittäin haitallisia iskusitkeyden kannalta. Homogeeninen, pääosin martensiittinen mikrorakenne takasi parhaat särmäystulokset. Huonoimmat särmäystulokset havaittiin näytteissä, joissa mikrorakenne oli epähomogeeninen sisältäen paljon ferriittiä, tai kun pinnan voimakas {112}–leikkaustekstuuri yhdistettiin valssaussuunnassa venyneisiin MA-saarekkeisiin pintakerroksissa

High chromium cast iron (HCCI) is considered as one of the most useful wear resistance materials and their usage are widely spread in industry. The mechanical properties of HCCI mainly depend on type, size, number, morphology of hard carbides and the matrix structure (γ or α). The hypereutectic HCCI with large volume fractions of hard carbides is preferred to apply in wear applications. However, the coarser and larger primary M7C3 carbides will be precipitated during the solidification of the hypereutectic alloy and these will have a negative influence on the wear resistance. In this thesis, the Ti-alloyed hypereutectic HCCI with a main composition of Fe-17mass%Cr-4mass%C is studied based on the experimental results and calculation results. The type, size distribution, composition and morphology of hard carbides and martensite units are discussed quantitatively. For a as-cast condition, a 11.2μm border size is suggested to classify the primary M7C3 carbides and eutectic M7C3 carbides. Thereafter, the change of the solidification structure and especially the refinement of carbides (M7C3 and TiC) size by changing the cooling rates and Ti addition is determined and discussed. Furthermore, the mechanical properties of hypereutectic HCCI related to the solidification structure are discussed. Mechanical properties of HCCI can normally be improved by a heat treatment process. The size distribution and the volume fraction of carbides (M7C3 and TiC) as well as the matrix structure (martensite) were examined by means of scanning electron microscopy (SEM), in-situ observation by using Confocal Laser Scanning Microscope (CLSM), Transmission electron microscopy (TEM) and electron backscattered diffraction (EBSD). Especially for the matrix structure and secondary M7C3 carbides, EBSD and CLSM are useful tools to classify the fcc (γ) and bcc (α) phases and to study the dynamic behavior of secondary M7C3 carbides. In conclusion, low holding temperatures close to the eutectic temperature and long holding times are the best heat treatment strategies in order to improve wear resistance and hardness of Ti-alloyed hypereutectic HCCI. Finally, the maximum carbides size is estimated by using statistics of extreme values (SEV) method in order to complete the size distribution results. Meanwhile, the characteristic of different carbides types will be summarized and classified based on the shape factor.

QC 20130913

The work covers studying of influence of indexes of an ion-plasma vacuum-arc deposition method to the structure, composition and properties of Ti-Al-N/Zr-Nb-N/Cr-N multilayer nanostructured coatings (MNC). The average crystallites size within the layers is about 5-10 nm. Received coatings are featured by absence of any change in the composition and properties after heating up to 1000 ºС, the coatings hardness is up to 36,6GPa, Young's modulus of elasticity is up to 580 GPa, plastic work of deformation is up to 64 %, adhesive strength is about 100 N and coefficient of friction is 0,45. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35318

This thesis work was performed at AB Sandvik Coromant and aimed to enhance the knowledge about the relationships between the performance of TiN and TiAlN-coated cutting tools in metal turning and their mechanical and chemical properties. Measurements of coating material properties and turning wear tests in annealed tool steel Sverker 21, stainless steel 316L, grey cast iron V314 and nodular cast iron SS0727 were performed. The cutting temperatures were estimated from FEM-simulations. To find the dominant wear mechanism and identify the properties that are most important for the resistance against that particular wear, a correlation analysis was performed together with a wear study using LOM, SEM and EDS. The results show that relations between cutting performance and mechanical properties and/or composition of the coatings can be established. The FEM-simulations suggested that the peak tool temperature was highest, ~750°C, for turning in 316L and lowest for turning in Sverker 21, ~300°C. Turning in cast iron resulted in temperatures around 500-550°C. A mechanism for the growth of the crater on inserts tested in stainless steel 316L is proposed. Wear due to thermo-mechanical load and adhesion are believed to be the dominating wear mechanisms. The performance of the tool showed a high correlation to the composition of the coatings, with a decreased tool life for higher Al-contents. The reason for this might lie in an increased brittleness of these coatings, accelerating formation of lateral cracks above the crater. Calculated ratios of bulk and shear modulus suggests an increased brittleness for higher Al-contents. A higher tendency to stick to the work piece material might also contribute to a decrease in tool life. An Increased Al-content could also drive the formation of c-AlN to h-AlN, causing even higher wear rates. The coatings with higher substrate bias showed an enhanced performance, even though the crack pattern was worsened for these variants. The reason for the enhanced performance seen for these variants might instead originate in an enhanced adhesion to the substrate. In the flank wear resistance test in Sverker 21 the Al-content proved to be important, with an improved performance for higher Al-contents. In contrast to the test in 316L, a change in bias or hardness had no effect on the performance in this test. Scratch patterns on the flank supports that an abrasive wear mechanism is present, but no correlation between hardness and tool life could be obtained. Either some other material property than hardness is of importance for the abrasive resistance in this test, or another wear mechanism, occurring simultaneously with abrasion, is the wear rate deciding. The second part of this thesis work was to evaluate the ability of a quantum mechanical computational method, density functional theory, to predict material properties. The method predicts the lattice parameters and bulk moduli in excellent agreement with experimental values. The method also well predicts other elastic properties, with results consistent with reference values. There seems to be a constant shift of about 50-100 GPa between the calculated elastic modulus and the experimentally measured values, probably originating in contributions from grain boundaries, texture, stresses and defects present in the real coatings, and possibly also in errors in the experimental method due to an influence from the substrate. The calculated hardness values did not follow the trend of an increased hardness for TiAlN compared to TiN, which is seen in experiments.

В даному дипломному проекті розглядається питання пов’язане з підвищенням зносостійкості штоку гідроциліндра плазмовим напиленням. Проведено аналіз умов роботи та експлуатації штоку гідроциліндра, досліджено технологічні характеристики основного та матеріалу для напилення. Розроблено технологію підвищення зносостійкості, яка забезпечує якісне формування напиленого шару та високі зносостійкі властивості. В розділі з охорони праці висвітлено питання підвищення електробезпеки, газової безпеки та покращення умов праці персоналу. Записка вміщує 93 сторінки машинописного тексту, 24 рисунків, 23 таблиць, 1 додаток, 15 джерел літератури.
In this thesis project the issue related to increase wear resistance of hydraulic cylinder with plasma spraying is indicated. The analysis of the working conditions and the operating of compressor stem has been studied. The technological characteristics of the basic and surfacing materials have been investigated. The technology of restoration that ensures a high-quality formation of the deposited layer, providing the high wear resistant properties, has been developed. In the section on Occupational Health and Safety the issues of enhance electrical and gas safety and improvement of the working conditions of the personnel are highlighted. The note contains 93 pages of typewritten text, 8 figures, 10 tables, 2 appendixes, 15 sources of literature.

Diamond-like Carbon (DLC) coatings represent an interesting research subject for various groups of researchers having interests in surfaces tribology and corrosion. This paper discusses issues relating to the friction and mechanical behaviour, for 4 types of DLC coating systems deposited on heat treatable steel hardened and high-tempered (a multilayer of WC/C (a-C:H:W); CrC+a-C:H, a single layer of a-C:H, plasma nitriding + Si doped DLC (PN+Si-a-C:H). These films were synthesized using a single or a combined process consisting in either r. f. reactive magnetron sputtering or/followed by Plasma Assisted Chemical Vapour Deposition (PACVD). The tribological properties (friction coefficient) were obtained and discussed in correlation with the mechanical properties (the adherence, the nanoindentation hardness) and thickness When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/34917

The desire to replace missing teeth with the aim to improve health and quality of life dates back to a thousand years ago. Although research on dental crown designs, materials and techniques has increased in recent years and is expected to grow in the future. In the past few decades, dental crown studies have gained high importance in dentistry due to their functionality, biocompatibility and good mechanical properties. This paper provides a comprehensive review of history and evolution of dental crowns. The goal of this study is to understand the dental crown materials and the differences in their properties with goals to facilitate the optimal selection and to support further development. It also describes the different methods by which wear is tested on these crowns. Finally, it describes the current technologies used for the analysis, and a comparative study is performed on various dental crown materials and it is demonstrated that the wear resistance is different for different materials.

High chromium cast iron (HCCI) is considered as one of the most useful wear resistance materials and their usage are widely spread in industry. The wear resistance and mechanical properties of HCCI mainly depend on type, size, number, morphology of hard carbides and the matrix structure (γ or α). The Hypereutectic HCCI with large volume fractions of hard carbides is preferred to apply in wear applications. However, the coarser and larger primary M7C3 carbides will be precipitated during the solidification of the hypereutectic alloy and these will have a negative influence on the wear resistance. In this thesis, the Ti-added hypereutectic HCCI with a main composition of Fe-17mass%Cr-4mass%C is quantitatively studied based on the type, size distribution, composition and morphology of hard carbides and martensite units. A 11.2μm border size is suggested to classify the primary M7C3 carbides and eutectic M7C3 carbides. Thereafter, the change of the solidification structure and especially the refinement of carbides (M7C3 and TiC) size by changing the cooling rates and Ti addition is determined and discussed. Furthermore, the mechanical properties of hypereutectic HCCI related to the solidification structure are discussed. Mechanical properties of HCCI can normally be improved by a heat treatment process. The size distribution and the volume fraction of carbides (M7C3 and TiC) as well as the matrix structure (martensite) were examined by means of scanning electron microscopy (SEM) and electron backscattered diffraction (EBSD). Especially for the matrix structure, EBSD is a useful tool to classify the fcc (γ) and bcc (α) phases. In conclusion, low holding temperatures close to the eutectic temperature and long holding times are the best heat treatment strategies in order to improve wear resistance and hardness of Ti-alloyed hypereutectic HCCI.

QC 20121130

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Dissertação (Mestrado)
IPEN/D
Universidade Mackenzie. Departamento de Engenharia de Materiais, São Paulo

Dense, with good adhesion to the substrate, hard, wear-resistant coatings from the powder of Al2O3 were obtained on the surface of the steel (STE255) by using the cumulative-detonation device. The results of investigations of the structure and physico-mechanical properties of the coatings by using scanning, optical microscopy, X-ray phase analysis, microhardness and tribological tests are presented. It was found that optimization of plasma spraying to helps reduce the porosity of coatings of Al2O3 less than 1 % and to increase the hardness of them to 1250 HV0.3. The tribological investigations have shown that the coatings of Al2O3 significantly increase the wear resistance of the sample STE255 and provide a low ability to wear out the coating. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35467

The current study focuses on improving the wear resistance of femoral head component and enhancing the osseo-integration properties of femoral stem component of a hip implant made of a new generation low modulus alloy, Ti-35Nb-7Zr-5Ta or TNZT. Different techniques that were adopted to improve the wear resistance of low-modulus TNZT alloy included; (a) fabrication of graded TNZT-xB (x= 0, 1, 2 wt%) samples using LENS, (b) oxidation, and (c) LASER nitriding of TNZT. TNZT-1B and TNZT-O samples have shown improved wear resistance when tested against UHMWPE ball in SBF medium. A new class of bio-ceramic coatings based on calcium phosphate (CaP), was applied on the TNZT sample surface and was further laser processed with the objective of enhancing their osseo-integration properties. With optimized LASER parameters, TNZT-CaP samples have shown improved corrosion resistance, surface wettability and cellular response when compared to the base TNZT sample.

Multilayered coatings based on TiN/ZrN with different thickness of bilayers were deposited on steel substrates using vacuum arc deposition of a cathodes (C-PVD method). Thickness of bilayer strongly depended on deposition conditions and varied in the range 39 – 305 nm, total thickness of the coatings were 11-19 μm. Mechanical and tribotechnical characteristics of the coatings were investigated in the paper as well as its microstructure. Influence of the bilayer thickness on the properties of the coatings were explored.

Мета роботи – це здешевлення виробництва за рахунок заміни дорожчого матеріалу на більш дешевий аналог не втрачаючи технологічні та механічні властивості при заміні. Деталь – штамп для холодного деформування.

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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
FAPESP:98/05906-6

Neste trabalho foi investigado o processamento e propriedades mecânicas e tribológicas do compósito cerâmico Al2O3- NbC com o objetivo de desenvolver um compósito cerâmico com melhores propriedades do que a alumina pura. Como material para comparação foi utlizado a alumina que é uma cerâmica tradicionalmente aplicada onde é necessária elevada resistência mecânica e ao desgaste. A composição Al2O3-0,5%wtY2O3-20%wtNbC, que origina o compósito, passou por moagem e mistura em moinho tipo atrittor e secagem em evaporador rotativo. O pó obtido foi caracterizado quanto a distribuição granulométrica e morfologia. A alumina seguiu a rota tradicional de moagem e mistura em moinho de bolas, secagem em spray dryer; e mesma caracterização realizada para o compósito. Foi realizado estudo da sinterização em dilatômetro para os dois materiais com intuito de determinar as condições ideais de sinterização. Por meio de prensagem uniaxial seguida de prensagem isostática a frio foram confeccionadas amostras na forma de discos e pinos. Os materiais densos foram obtidos por sinterização normal sendo que a alumina ao ar e o compósito em atmosfera de argônio. As fases formadas no dois materiais foram determinadas por difração de raios X. As microestruturas foram estudas em microscópio eletrônico de varredura nas superfícies polidas e atacadas. Entre as propriedades mecânicas foram medidas o módulo elástico, a dureza e a tenacidade à fratura por meio de impressões Vickers. O compósito desenvolvido apresentou valores superiores em todas estas propriedades em relação a alumina. O estudo do comportamento tribológico foi realizado por meio do deslizamento de pinos, com extremidade cônica, de alumina e do compósito cerâmico sobre discos de alumina. Os ensaios foram realizados com a velocidade de 0,4m/s e com carregamento, por meio de peso morto, de 10N sob diferentes níveis de umidade relativa ( 26,8; 48 e 76,3%). O coeficiente de atrito cinético médio, assim como a taxa de desgaste, diminuiu em todos os ensaios com o aumento da umidade relativa, para os dois materiais. Este comportamento foi relacionado com a formação de uma camada na interface de contato entre as superfícies do pino e do disco de hidróxido de alumínio. O compósito demostrou maior resistência ao desgaste em todas as condições tribológicas estudadas. O compósito cerâmico desenvolvido claramente possui boas perspectivas como um novo material cerâmico em importantes aplicações técnicas.
In the present work processing, and mechanical and tribological properties of a ceramic composite Al2O3-NbC were investigated in order to develop a ceramic material with superior properties. Alumina was chosen as a reference since it is a traditional ceramic material for applications where elevated mechanical properties and wear resistance are required. The composition Al2O3 - 0.5 wt%Y2O3-20 wt%NbC was prepared by attrition milling followed by drying in a rotaevaporator. The resulting powder mixture was characterized for granulometry and powder particles morphology. Alumina was processed according to the traditional route of ball milling followed by passing through a spray drier, and the processed powder was then characterized the same way as the composite. Dilatometry was accomplished for both materials in order to define the ideal sintering conditions. Samples with the shape of discs and pins were compacted by uniaxial pressing followed by cold isostatic pressing. Densification was achieved by sintering in air and in argon for alumina and the composite, respectively. Phase composition of sintered materials was studied by X-ray diffraction (XRD). Microstructure was investigated by means of scanning electron microscopy (SEM) on polished and etched surfaces. Materials were also characterized for a number of mechanical properties, in particular for Young modulus, hardness, and fracture toughness by Vickers indentation method. The developed composite exhibited superior mechanical properties as compared to alumina. Tribological behavior was investigated by means of a sliding pin on disk test with pins of a conical shape prepared both from alumina and the composite, and an alumina disk. Tests were performed with the sliding speed of 0.4 m/s and 10N load under varying humidity conditions (26.8; 48, and 76.3%). Both the mean coefficient of friction and the wear rate diminished in all tests with the increase of humidity for both materials. Such behavior was attributed to a aluminum hydroxide layer formation between the pin and the disk surfaces. The developed composite exhibited better wear resistance under all tribologic conditions studied. The developed ceramic composite obviously has good perspectives as a new material for a variety of important technical applications.

O ADI constitui-se no desenvolvimento mais recente na família dos ferros fundidos nodulares. Com o tratamento de austêmpera, consegue-se produzir uma microestrutura única, constituída de ferrita acicular e austenita estável rica em carbono, a ausferrita, proporcionando alta resistência mecânica aliada à ductilidade e tenacidade, além de boa resistência à fadiga e ao desgaste. Neste trabalho estudou-se o efeito dos elementos de liga Cu, Ni e Mo nas propriedades mecânicas e austemperabilidade do ADI. Foram produzidas barras cilíndricas de ferros fundidos nodulares nos diâmetros de Ø2, Ø3 e Ø4 ligadas com Cu, Cu-Ni, Cu-Ni- Mo respectivamente. Os corpos de prova utilizados nos ensaios de tração, impacto e microdesgaste foram retirados a meio-raio das barras. Posteriormente, cada conjunto de corpo de prova foi austenitizado a 890°C durante 2 horas, sendo em seguida submetido a uma condição de tratamento de austêmpera específica, combinando temperaturas de austêmpera de 300 e 360°C e tempos de 1, 2, 3 e 4 horas. Realizou-se análises microestruturais ópticas e por microscopia eletrônica de varredura para correlacionar propriedades mecânicas com a microestrutura. Na análise de austemperabilidade, as barras cilíndricas foram austemperadas para verificar a variação de microestrutura em função do raio da barra. Verificou-se que a temperatura de austêmpera exerce forte influência na microestrutura do ADI e consequentemente nas propriedades de tração, ductilidade, tenacidade e resistência ao desgaste. Nos tratamentos a 300°C obteve-se uma microestrutura mais refinada, com maior quantidade de ferrita acicular, responsável pela maior resistência mecânica e resistência ao desgaste; enquanto que no tratamento realizado a 360°C obteve-se uma microestrutura mais grosseira, com maior quantidade de austenita estável, responsável pela melhor ductilidade e tenacidade. Nos tempos de austêmpera analisados, não ocorreram variações significativas nas microestruturas e propriedades mecânicas. A resistência mecânica e a tenacidade decresceram com a adição de Mo, provavelmente devido à segregação deste elemento, mas a resistência ao desgaste a seco e a austemperabilidade foram mais efetivas em comparação com ligas contendo Cu e Cu-Ni. No ensaio de desgaste usando-se lubrificante, o ADI ligado com Cu-Ni austemperado a 360°C apresentou uma resistência ao desgaste um pouco inferior a de um aço 17CrNiMo6 cementado.
The ADI is the most recent development in the nodular iron family. With the austempering treatment, a unique microstructure, consisting of acicular bainite ferrite and stable austenite rich in carbon, named ausferrite is produced. This microstructure provides high mechanical strength combined with ductility, toughness and good fatigue and wear resistances. In this work, the effect of alloying elements Cu, Ni and Mo on the mechanical properties and austemperability of the ADI were studied. To conduct these studies, cylindrical bars with diameters of Ø2\", Ø3\" and Ø4\" were cast with Cu, Cu-Ni and Cu-Ni-Mo alloying, respectively. The samples were then manufactured by removing specimens from the bar midradius position. Subsequently, each set of the samples was austenitized at 890°C for 2 hours, and then subjected different conditions of austempering treatment. These treatments were developed by combining austempering temperatures of 300 and 360°C with austempering times of 1, 2, 3 and 4 hours. Microstructural analysis was carried out using optical and scanning electron microscopy to correlate mechanical properties with the microstructure. In the austemperability analysis, cylindrical bars were austempered (at 360°C for 3 hours) to correlate microstructure and radius. The experimental results showed that the austempering temperature exerts strong influence on the ADI´s microstructure and consequently on the mechanical properties. The austempering temperature of 300°C produced the best results, a refined microstructure, with a greater amount of acicular ferrite, responsible for greater strength and wear resistance. The austempering temperature of 360°C produced a coarse microstructure, with larger amount of austenite and responsible for better ductility and toughness. The austempering times used in this work did not produce significant variations in the properties and microstructures. Regarding alloying elements, the mechanical strength and toughness decreased with the addition of Mo, probably due to the segregation of this element, but the wear resistance and austemperability were more effective when compared with the alloys containing Cu and Cu-Ni. In the lubricated wear test, the ADI alloyed with Cu-Ni and austempered at 360°C presented a wear resistance only a fraction lower than a cemented 17CrNiMo6 steel.

Orientador: Amauri Garcia
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: A procura por relações funcionais correlacionando parâmetros microestruturais e o comportamento mecânico de ligas metálicas é fundamental para a pré-programação do produto final. O presente estudo pretende contribuir para o entendimento sobre a influência dos parâmetros microestruturais na resistência ao desgaste e nas propriedades mecânicas de ligas de dois sistemas binários: AI-Sn e AI-Si. Tais ligas são bastante usadas em aplicações de engenharia, tais como mancais e camisas de cilindro de motores de combustão, respectivamente. Apesar do grande uso das ligas do sistema AI-Sn como material tribológico, são escassos os estudos sobre o desenvolvimento microestrutural destas ligas na literatura. Neste estudo, quatro ligas hipoeutéticas do sistema AI-Sn e três ligas hipoeutéticas do sistema AI-Si foram submetidas a solidificação unidirecional, na direção vertical e sentido ascendente, sob condições transitórias de fluxo de calor. Os espaçamentos dendríticos primários (À1) e secundários (À2) foram medidos nas direçõe.s transversal e longitudinal dos lingotes, respectivamente, e correlacionados com as variáveis térmicas que atuaram durante a solidificação. Uma abordagem teórico-experimental foi desenvolvida para determinar quantitativamente_as variáveis térmicas, tais como: coeficiente de transferência de calor na interface metal/molde, velocidade de deslocamento da isoterma liquidus, gradientes térmicos, taxa de resfriamento e tempo local de solidificação. Este estudo também aborda a influência do teor de soluto nos espaçamentos dendríticos das ligas estudadas. Os dados experimentais obtidos, concementes à solidificação das ligas AI-Sn, são comparados com modelos de crescimento dendrítico existentes na literatura. O comportamento mecânico das ligas AI-Sn e AI-Si foi analisado por meio de ensaios de tração e de desgaste. O ensaio de desgaste utilizado foi o ensaio de micro-abrasão por esfera rotativa fixa, sob condições a seco (sem óleo lubrificante ou solução abrasiva). As amostras submetidas aos ensaios de desgaste foram retiradas na direção transversal dos lingotes. A condição a seco foi adotada para impedir a interferência de elementos interfaciais na resposta da microestrutura com relação ao desgaste mecânico. O volume de desgaste é o parâmetro quantificador da resistência ao desgaste e, são obtidas equações que correlacionam o volume de desgaste com espaçamentos dendríticos, levando em consideração o tempo de ensaio, que está relacionado com a distância de deslizamento.
Abstract: The search for relationships between microstructural parameters and mechanical behavior of alloys is fundamental for the pre-programming of final properties of as-cast components. The present study aims to contribute to the understanding about the influence of microstructural parameters on the wear resistance and mechanical properties of alloys of two binary systems: Al-Sn and AI-Si. Such alloys are widely used in engineering applications, especially as bearing components such as journal bearings and cylinder liners, respectively. Despite the wide use of Al-Sn alloys as bearing materiaIs studies on the microstructural development of such alloys are rare.. In the present study, four Al-Sn and three AI-Si hypoeutectic alloys were directionally solidified under upward unsteady state heat flow conditions. The primary (1,,1) and secondary (Â.2) dendrite arm spacings were measured along the castings length and correlated with transient solidification thermal variables. A combined theoretical and experimental approach has been used to quantitatively determine such thermal variables, i.e., transient metaVmold heat transfer coefficients, tip growth rates, thermal gradients, tip cooling rates and local solidifÍcation time. This study also focuses on the dependence of dendrite arm spacings on the alloy solute content. Furthermore, the experimental data conceming the solidification of AI -Sn alloys are compared with the main predictive dendritic models from the literature. The mechanical behaviors ofthe AI-Sn and AlSi alloys were analyzed by wear and tensile tests. Micro-abrasive wear tests under dry sliding conditions and by using a fixed rotating sphere were applied to transversal samples collected along the casting. The dry condition is adopted to prevent effects of interfacial elements such as abrasive slurry or lubricant oil on the microstructural response during the tests. The wear volume was used to evaluate the wear resistance. Afterwards, equations correlating the wear volume and the dendritic arm spacing have been proposed taking into account the influence of time (sliding distance).
Doutorado
Materiais e Processos de Fabricação
Doutor em Engenharia Mecânica

On a cherche a mettre en evidence les differents effets de la microstructure et des proprietes intrinseques des materiaux etudies (al::(2)o::(3), sic, sialon) sur les mecanismes d'enlevement de matiere lors de l'usure par frottement a sec. Des modifications microstructurales ou morphologiques ont ete tentees par divers traitements de frittage ou de post-frittage. En particulier, on a etudie les effets du pressage isostatique chaud et de l'implantation ionique sur les proprietes mecaniques et tribologiques du sialon fritte. On a developpe un essai de rayage pour remplacer les essais d'indentation mal adaptes du fait du role joue par les debris d'usure consideres comme un troisieme corps. On a etudie les mecanismes creant ces debris ou les faisant evoluer. Il apparait que le rayage et l'usure des ceramiques, deux phenomenes lies a la creation de debris (avec ou sans circulation), doivent etre consideres comme faisant appel principalement au caractere plastique de debris agglomeres

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.17.03 – технічна електрохімія. – Національний технічний університет “Харківський політехнічний інститут”, Харків, 2015 р. Дисертацію присвячено розробці технології електрохімічного формування функціональних покриттів сплавами заліза з молібденом і вольфрамом із цитратних електролітів для одержання матеріалів з високою корозійною стійкістю, фізико-механічними та трибологічними характеристиками. На підставі аналізу кінетичних закономірностей встановлено механізм електрохімічного одержання сплавів Fe-Mo і Fe-Mo-W, за яким співосадження заліза з молібденом і вольфрамом із цитратного електроліту в інтервалі pH 3,0–4,0 відбувається за двома маршрутами: перший – стадійне відновлення металів із гетероядерних комплексів складу [FeHCitMO₄]⁻, (М = Mo, W), розряд яких супроводжується хімічною реакцією вивільнення ліганду, а другий – стадійне відновлення феруму (ІІІ) із цитратних електролітів переважно з адсорбованих комплексів складу [FeHCit]⁺, й частково – з FeOH²⁺, та супроводжується хімічною стадією вивільнення ліганду. Експериментальні дослідження функціональних властивостей електролітичних сплавів довели, що покриття Fe-Mo і Fe-Mo-W володіють підвищеною корозійною стійкістю у кислому середовищі, що зумовлене кислотним характером оксидів тугоплавких компонентів, у нейтральному – опором пітинговій корозії, що загалом перевищує хімічний опір сталі та чавуна. Запропоновані електролітичні сплави переважають за мікротвердістю основу зі сталі у 2–3 рази, а чавуну – у 4–5 рази, причому вміст вольфраму забезпечує зростання механічних та триботехнічних характеристик. Мікротвердість, антифрикційні властивості та зносостійкість електролітичних сплавів Fe-Mo і Fe-Mo-W зростають за рахунок утворення аморфної структури. Запропоновано технологічну схему електрохімічного формування функціональних покриттів сплавами заліза з молібденом і вольфрамом та розроблено технологічні інструкції для процесів їх осадження.
Thesis for granting the Degree of Candidate of Technical sciences in speciality 05.17.03 – Technical Electrochemistry. – National Technical University “Kharkiv Politechnical Institute”, 2015. The thesis is devoted to the development of technology for iron alloys electrochemical functional coatings with molybdenum and tungsten electrodeposition from citrate electrolyte to produce materials with high corrosion resistance, physical, mechanical and tribological properties. On the basis of kinetic regularities the mechanism of Fe-Mo, Fe-Mo-W alloys’ formation was established as co-precipitation of iron with molybdenum and tungsten in the range pH 3,0–4,0 happening on two routes, one-alloying metals reduction from heteronuclear complexes [FeHCitMO₄]⁻ is accompanied by chemical reaction of ligand releasing, and the second-reduction of iron (III) from the adsorbed complexes [FeHCit]⁺ and in part – from FeOH²⁺ accompanied by the chemical stage of ligand release. Experimental study of the electrolytic alloys functional properties have shown the high corrosion resistance of FeMo and Fe-Mo-W coatings in acidic and neutral media stimulated by acidic nature of refractory oxide components which exceeds the resistance of steel and cast iron. Proposed electrolytic alloys dominated by microhardness steel substrates in 2–3 times, and cast iron – in 4–5 times, the increasing tungsten content provides increasing in physical, mechanical and tribological properties of electrolytic alloys due to the formation of amorphous structure. A technological scheme for electrochemical synthesis of iron alloys functional coatings with molybdenum and tungsten was designed and technological instructions were prepared for implementation.

Дисертація на здобуття наукового ступеня доктора технічних наук за спеціальністю 05.02.08 – технологія машинобудування (13 – механічна інженерія). – Національний технічний університет «Харківський політехнічний інститут», Харків, 2019. У дисертаційній роботі проведено комплекс досліджень, спрямованих на вирішення важливої науково-технічної проблеми в області технології машинобудування: розробка інноваційних та короткотривалих технологій поверхневого зміцнення деталей машин порошковими сумішами керованого складу для забезпечення експлуатаційних властивостей виробів на високому рівні при значному зниженні затрат на їх виготовлення. Наукова новизна отриманих результатів полягає у розробці наукових основ інноваційних та короткотривалих технологій поверхневого зміцнення деталей машин порошковими сумішами керованого складу, що дозволило вирішити актуальну науково-практичну проблему підвищення терміну служби деталей машин та інструменту: – вперше розраховано локальні максимуми поверхневої твердості та глибини дифузійних шарів сплавів і встановлено теоретичні оптимальні умови процесів дифузійного зміцнення, що дозволяє отримати конкретні технологічні параметри проведення хіміко-термічної обробки (ХТО) та забезпечити оптимальні характеристики дифузійних шарів; – вперше створено математичні моделі та номограми існуючих технологій поверхневого зміцнення сталей, що дозволило визначити конкретні умови ХТО (температуру і тривалість), виходячи із заданої глибини дифузійного шару або поверхневої твердості сталей, що суттєво впливає на ефективність реалізації процесів зміцнення; – вперше на основі використання інноваційних технологій і системного аналізу при мінімальних витратах, розроблено загальний методологічний підхід керування технологічними процесами поверхневого зміцнення деталей порошковими сумішами керованого складу при насиченні поверхневих шарів азотом, вуглецем і бором, це дозволило підвищити експлуатаційні властивості виробів при значному скороченні тривалості ХТО; – набули подальшого розвитку розроблені комплексні ХТО, які значно знижують крихкість борованих шарів за рахунок більш плавного зниження твердості від поверхні до серцевини виробів зі сталей, що дозволило підвищити експлуатаційні властивості виробів та термін служби деталей машин та інструменту на відміну від відомих методів ХТО, які підвищують лише поверхневу твердість; – вперше розроблено математичну модель розподілу температури за глибиною дифузійного шару, що дозволило визначити характер залежностей та отримати дані про розподіл температури за глибиною виробу при різних технологічних режимах обробки; – удосконалено технологію борування з паст титанових сплавів за рахунок використання нанодисперсного насичувального середовища, що дозволило скоротити процес борування у 2-3 рази та скоротити технологічний процес виготовлення деталей за рахунок поєднання двох операцій: борування і гартування титанового сплаву; – запропоновано розв’язання крайових задач дифузії методом граничних елементів, що дозволило вперше створити математичну модель розподілу концентрації бору за товщиною зміцненого шару титанового сплаву; − удосконалено технологію інтенсифікації процесів ХТО методами нагрівання струмами високої частоти та за рахунок попередньої лазерної обробки деталей, що дозволило отримати високі експлуатаційні властивості поверхневих шарів при значному скороченні тривалості обробок. Практичне значення роботи полягає у розробці технологій комбінованого зміцнення поверхневих шарів деталей зі сплавів. На основі комплексу проведених теоретичних та експериментальних досліджень, сформульованих принципів, закономірностей і положень отримані наступні практичні результати: 1. Спосіб комбінованої обробки сталевих виробів, що включає попередню лазерну обробку поверхні матеріалу з потужністю лазерного випромінювання -1,0±0,1 кВт, швидкістю пересування лазерного променя - 0,5-1,5 м/хв. з наступним азотуванням. Крім цього, азотування проводять в середовищі меламіну з 3-5% фтористого натрію при температурі 530-560 °C протягом 2-3 годин (патент України №111066). 2. Спосіб дифузійного борування сталевих виробів, що включає попереднє нанесення на поверхню обмазки, в склад якої входить боровмісна речовина, активатор фторид натрію і зв'язуюча речовина розчину клею БФ в ацетоні, і нагрівання струмами високої частоти. При цьому в обмазці як боровмісну речовину використовують поліборид магнію або аморфний бор і додатково введено активатор фторид літію (патент України №116177). 3. Спосіб поверхневого зміцнення сталевих виробів, що включає нанесення на поверхню деталі обмазки, до складу якої' входить боровмісна речовина і активатор, сушіння і нагрівання струмами високої частоти. В обмазці як боровмісну речовину використовують аморфний бор і активатор фторид літію. Нагрівання проводять при температурі 800-1100 °С протягом 1-5 хвилин (патент України №116178). 4. Спосіб отримання твердого покриття на поверхні сталевих виробів, що включає попередню обробку поверхні матеріалу та борування. Проводять попередню лазерну обробку поверхні матеріалу з наступним боруванням в середовищі полібориду магнію, активаторами: фтористий натрій і фтористий літій (патент України №116116). 5. Сплав на основі заліза з ефектом пам'яті форми, що містить: залізо, марганець, кремній, вуглець, хром, нікель, кобальт, мідь, ванадій, ніобій, молібден. При цьому до сплаву додатково введено сірку та фосфор (ваг. %): марганець від 4 до 20; кремній від 1,0 до 4,5; вуглець від 0,1 до 1,0; хром від 10,0 до 25,0; нікель від 1,0 до 10,0; кобальт від 1,0 до 10,0; мідь від 1,0 до 4,0; ванадій від 0,5 до 2,0; ніобій від 0,3 до 1,5; молібден від 0,5 до 2,0; сірка до 0,01; фосфор до 0,045; залізо решта (патент України №116117). 6. Склад для борування сталевих виробів, що містить аморфний бор, тетрафтороборат калію, нітрид бору і доломіт (патент України №117775). 7. Спосіб поверхневого зміцнення титанових сплаві, що включає насичення поверхневих шарів компонентами боровмісного середовища, до складу якого входить боровмісна речовина та активатор, і нагрівання. Насичення поверхневих шарів здійснюють компонентами боровмісного середовища, яке складається з аморфного бору і фториду літію (патент України №117770). 8. Дисперсійно-твердіючий сплав на основі заліза з ефектом пам'яті форми, що містить: залізо, марганець, кремній, вуглець, ванадій, ніобій, вольфрам. Додатково введено алюміній, мідь, нікель, хром, сірку та фосфор (патент України №117757). 9. Розроблені технологічні процеси ХТО були впроваджені для підвищення поверхневої твердості сталевих виробів на ТОВ «АСТИЛ М» (м. Харків), що дозволило підвищити зносостійкість втулки у 1,5 рази після нітроцементації, у 4,3 рази після послідовній нітроцементації та боруванні, у 5 разів після цементації, нітроцементації та боруванні та у 2 рази після боруванні з нагріванням СВЧ у порівняні зі втулкою без поверхневого зміцнення (Акт впровадження від 05.10.2017 р.). 10. Розроблені технологічні процеси комбінованого зміцнення були впроваджені для підвищення поверхневої твердості сталевих виробів на ПАТ «Харківський машинобудівний завод «Світло шахтаря» (м. Харків). Виробничими випробуваннями встановлено, що запропоновані ефективні технологічні процеси комбінованого зміцнення поверхневого шару сталевих виробів дозволили значно прискорити технологічні процеси хіміко-термічної обробки у 2-10 разів, що привело до зменшення витрат на їх проведення за рахунок економії електричної енергії (Акт впровадження від 17.10.2017 р.). 11. Розроблені технологічні процеси були впроваджені на ТОВ «НВЦ ЄТМ» (м. Харків), що дозволило підвищити зносостійкість втулки у 1,5 рази після нітроцементації, у 4,3 рази після послідовній нітроцементації та боруванні (Акт впровадження від 31.10.2017 р.). 12. Прийняті для впровадження в виробництві розроблені номограми, які дозволяють визначити конкретні умови газового азотування (температуру і тривалість) виходячи із заданої глибини азотованого шару або поверхневої твердості виробів зі сталі 38Х2МЮА на ПАТ «Харківський машинобудівний завод «Світло шахтаря» (м. Харків). Встановлено, що запропоновані номограми дозволили значно спростити роботу інженера-технолога, а також номограми дозволили вирішувати зворотну задачу, а саме, оцінити можливу товщину зміцненого шару і поверхневу твердість при одночасному впливі температури і тривалості газового азотування (Акт впровадження від 15.11.2017 р.). 13. Розроблений ефективний технологічний процес нітроцементації у порошковій макродисперсній суміші для підвищення експлуатаційної стійкості зубчастого колеса зі сталі 38Х2МЮА на АТ «Харківський тракторний завод» (м. Харків). Встановлено, що використання макродисперсної суміші прискорило процес хіміко-термічній обробки у 1,5-2 рази при отриманні властивостей поверхневого шару виробу таких, як і після традиційного процесу нітроцементації, що дозволило зменшити витрати на проведення хіміко-термічної обробки у 2 рази (Акт впровадження від 24.01.2018 р.). 14. Розробки, виконані в дисертації, впроваджені в навчальний процес для студентів механіко-технологічного факультету НТУ «ХПІ» спеціальностей 131 «Прикладна механіка» спеціалізації 131-09 «Обладнання та технології ливарного виробництва» та 151 «Автоматизація та комп’ютерно інтегровані технології» спеціалізації 151-07 «Комп’ютеризовані системи управління технологічними процесами» (Акт впровадження від 20.12.2017 р.).
The thesis for the scientific degree of doctor of technical sciences, specialty 05.02.08 – technology of mechanical engineering (13 – mechanical engineering). – National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2019. In the thesis a set of studies was aimed at solving an important scientific and technical problem in the field of engineering technology: the development of innovative and short-term technologies of machine parts surface hardening with controlled composition powder mixtures to ensure the performance properties of products at a high level with a significant reduction in the cost of their production. The scientific novelty of the results lies in the development of scientific foundations of innovative and short-term technologies of surface hardening of machine parts by powder mixtures of controlled composition, which allowed to solve the actual scientific and practical problem of increasing the service life of machine parts and tools: - for the first time, local maxima of surface hardness and depth of diffusion layers of alloys were calculated and theoretical optimal conditions of diffusion hardening processes were established, which allows obtaining specific technological parameters of the chemical and heat treatment (CHT) process and providing optimal characteristics of diffusion layers; - for the first time created mathematical models and nomograms of existing technologies of surface hardening of steels, which allowed to determine the specific conditions of the CHT process (temperature and duration), based on a given depth of the diffusion layer or surface hardness of steels, which significantly affects the effectiveness of the implementation of strengthening processes; - for the first time through the use of innovative technologies and systems analysis at minimal cost, developed a general methodological approach for control of technological processes of surface hardening of parts by the powder mixtures of controlled composition at saturation of surface layers with nitrogen, carbon and boron, it is possible to improve the performance properties of products with a significant reduction in the CHT duration; – further development of the developed CHT complex, which significantly reduces the fragility of boriding layers due to a more gradual decrease in hardness from the surface to the core products of steels, thus improving the operational properties of the goods and service life of machine parts and tools in contrast to known methods of the CHT, which only increase surface hardness; - for the first time, a mathematical model of temperature distribution over the depth of the diffusion layer was developed, which made it possible to determine the nature of the dependences and obtain data on the temperature distribution over the depth of the product at different processing modes; – improved boriding technology with pastes of titanium alloys through the use of nanodispersed saturating environment, thereby reducing the boriding process to 2-3 times and to shorten the manufacturing process of components by combining two operations: boriding and hardening a titanium alloy; - solutions of boundary-value problems of diffusion by the boundary element method are proposed, which allowed for the first time to create a mathematical model of the distribution of boron concentration over the thickness of the hardened layer of a titanium alloy; - the technology of intensification of processes by CHT of heating by high-frequency currents and by means of preliminary laser processing of details was improved, which allowed to obtain high performance properties of surface layers with a significant reduction in the duration of treatments. The practical value of the work is to develop a technology of combined hardening of the surface layers of alloys making parts. The following practical results are obtained on the basis of a set of theoretical and experimental studies, formulated principles, regularities and the following practical results are obtained: 1. Method of combined processing of steel products, including advanced laser processing of material surface with the laser radiation power of -1.0±0.1 kW, the speed of movement of the laser beam of 0.5–1.5 m/min with subsequent nitriding. In addition, the nitriding is carried out in an environment of melamine with 3 to 5 % of sodium fluoride at a temperature of 530-560 °C for 2–3 hours (the patent of Ukraine No. 111066). 2. Method diffusion boriding steel products, including pre-application to the surface of the coating, which includes boriding substance, the activator sodium fluoride and a binder solution of glue BF in acetone, and heating by high frequency currents. In the coating as boriding substance use polyboride magnesium or amorphous boron, and optionally an activator is introduced lithium fluoride (the patent of Ukraine No. 116177). 3. Method of surface hardening steel parts comprising coating the surface of the part coating, which' is included boriding substance and activator, drying and heating by high frequency currents. In the coating as boriding substance use amorphous boron activator and lithium fluoride. The heating is carried out at a temperature of 800-1100 °C for 1-5 minutes (the patent of Ukraine No. 116178). 4. A method of producing a solid coating on the surface of steel products, including pre-processing the surface of the material and boriding. Carry out a preliminary laser treatment of the surface of the material with subsequent boriding in the environment polyboride magnesium, activators: sodium fluoride and lithium fluoride (the patent of Ukraine No. 116116). 5. The iron-based alloy with shape memory effect, contains: iron, manganese, silicon, carbon, chromium, nickel, cobalt, copper, vanadium, niobium, molybdenum. In this case, the alloy additionally introduced sulfur and phosphorus (weights. %): the manganese from 4 to 20; silicon 1.0 to 4.5; carbon 0.1 to 1.0; chromium, 10.0 to 25.0; nickel 1.0-10.0; cobalt 1.0-10.0; copper 1.0-4.0; vanadium 0.5 to 2.0; niobium from 0.3 to 1.5; molybdenum from 0.5 to 2.0; sulfur up to 0.01; phosphorus up to 0,045; iron-rest (the patent of Ukraine No. 116117). 6. Сomposition for boriding steel products containing amorphous boron, tetrafluoroborate potassium, boron nitride and dolomite (the patent of Ukraine No. 117775). 7. Method of surface hardening of titanium alloys, including a saturation of the surface layers of components boron environment, which includes boriding substance and the activator, and heating. The saturation of the surface layers is performed by components boron environment that consists of amorphous boron and lithium fluoride (the patent of Ukraine No. 117770). 8. The dispersion hardening iron-based alloy with shape memory effect, contains: iron, manganese, silicon, carbon, vanadium, niobium, tungsten. Included aluminum, copper, nickel, chromium, sulfur and phosphorus (the patent of Ukraine No. 117757). 9. Developed technological processes were introduced to improve the surface hardness of steel products at the limited liability company "ASTIL M" (Kharkіv), improving the durability of the sleeve by 1.5 times after nitrocarburizing, 4.3-fold after successive nitrocarburizing and boriding, 5 times after carburizing, nitrocarburizing and boriding and 2 times after boriding with microwave heating compared to a sleeve without surface hardening (the implementation Act from 05.10.2017). 10. Developed technological processes of the combined consolidation was implemented to improve surface hardness of steel products at Public company «Kharkiv machine-building plant "SVET SHAKHTYORA" (Kharkiv). Production tests have proved that the proposed effective technological processes of the combined hardening of surface layers of steel products will significantly accelerate the technological processes of chemical heat treatment in 2-10 times, led to reduced costs for them by saving electrical energy (the implementation Act from 17.10.2017). 11. Developed technological processes have been introduced at the limited liability company "Scientific-production Centre of the European mechanical engineering technology" (Kharkiv), thus improving the durability of the sleeve by 1.5 times after nitrocarburizing, 4.3-fold after successive nitrocarburizing and boriding (the implementation Act from 31.10.2017). 12. Adopted for implementation in production of developed nomograms that allow to define specific conditions of gas nitriding (temperature and duration) based on the desired depth of nitrided layer or the surface hardness of products of steel 38Cr2MoAl at Public company "Kharkiv machine-building plant «SVET SHAKHTYORA" (Kharkiv). Determined that the proposed nomograms greatly simplified the work of the engineer and these nomograms allowed to solve the inverse problem, to estimate the possible thickness of the hardened layer and surface hardness, at the same time of temperature and duration of gas nitriding (the implementation Act from 15.11.2017). 13. Developed an effective technological process of nitrocarburizing in microdisperse powder mixture to improve the operational stability of the toothed wheel of steel 38Cr2MoAl at private joint stock company "Kharkiv Tractor Plant". The use of microdisperse mixture accelerated the process of chemical-heat treatment by 1,5-2 times while getting the properties of the surface layer of the product such as after the nitrocarburizing, which reduced the costs of conducting chemical-thermal treatment by 2 times (the implementation Act from 24.01.2018). 14. The developments made in the thesis introduced in the educational process for students of mechanical engineering faculty of NTU "KhPI" special 131 "Applied mechanics" specialization 131-09 "Equipment and technology of foundry" and 151 "Automation and computer integrated technologies" specialization 151-07 "Computerized control of technological processes" (the implementation Act from 20.12.2017).

This thesis aims to compare the relationship of physical-mechanical properties of tool materials made of WC-Co sintered carbides with their resistance to initiation and propagation of thermal cracks. The paper presents the results of testing the basic physical-mechanical properties of the three samples sintered carbides with different percentage of Co binder. Next, this thesis describes the progress and results of quench experiment and cutting tests using, which was described resistance of the tested samples to thermal and mechanical shock, depending on the values of physical-mechanical properties.

Дисертація на здобуття наукового ступеня доктора технічних наук за спеціальністю 05.02.08 – технологія машинобудування (13 – механічна інженерія). – Національний технічний університет «Харківський політехнічний інститут», Харків, 2019. У дисертаційній роботі проведено комплекс досліджень, спрямованих на вирішення важливої науково-технічної проблеми в області технології машинобудування: розробка інноваційних та короткотривалих технологій поверхневого зміцнення деталей машин порошковими сумішами керованого складу для забезпечення експлуатаційних властивостей виробів на високому рівні при значному зниженні затрат на їх виготовлення. Розроблено загальний методологічний підхід керування технологічними процесами поверхневого зміцнення деталей порошковими сумішами керованого складу при насиченні поверхневих шарів азотом, вуглецем і бором на основі використання інноваційних технологій і системного аналізу при мінімальних витратах, що дозволило підвищити експлуатаційні властивості виробів при значному скороченні тривалості ХТО. Розроблено комплексні ХТО, які значно знижують крихкість борованих шарів за рахунок більш плавного зниження твердості від поверхні до серцевини виробів зі сталей для підвищення експлуатаційних властивостей виробів та терміну служби деталей машин та інструменту. Удосконалено технологію борування з паст титанових сплавів за рахунок використання нанодисперсного насичувального середовища, що дозволило скоротити процес борування у 2-3 рази та скоротити технологічний процес виготовлення деталей за рахунок поєднання двох операцій: борування і гартування титанового сплаву. Інтенсифіковано процеси ХТО методами нагрівання струмами високої частоти та за рахунок попередньої лазерної обробки деталей, що дозволило отримати високі експлуатаційні властивості поверхневих шарів при значному скороченні тривалості обробок.
The thesis for the scientific degree of doctor of technical sciences, specialty 05.02.08 – technology of mechanical engineering (13 – mechanical engineering). – National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2019. In the thesis a set of studies was aimed at solving an important scientific and technical problem in the field of engineering technology: the development of innovative and short-term technologies of machine parts surface hardening with controlled composition powder mixtures to ensure the performance properties of products at a high level with a significant reduction in the cost of their production. Mathematical models and nomograms of existing technologies of steels surface hardening were created to determine the specific conditions of ChTT (temperature and duration) based on a given depth of the diffusion layer or the surface hardness of steels, which significantly affects the efficiency of the strengthening processes. The general methodological approach of management of technological processes of details surface hardening by powder mixes of the controlled structure at saturation of surface layers with nitrogen, carbon and boron on the basis of use of innovative technologies and the system analysis at the minimum expenses was developed that allowed to increase operational properties of products at considerable reduction of ChTT duration. ChTT was designed the complex, which significantly reduces the fragility of boriding layers due to a more gradual decrease in hardness from surface to core products from steels to improve the operational properties of the goods and service life of machine parts and tools. It was created a mathematical model of the temperature distribution in the depth of the diffusion layer to determine the nature of the dependencies and obtain data on the temperature distribution in the depth of the product under different processing conditions. It was improved boriding pastes technology of titanium alloys through the use of nanodispersed environment, thereby reducing the boriding process 2-3 times and to shorten the manufacturing process of components by combining two operations: boriding and titanium alloy hardening. The solutions of boundary value diffusion problems by the boundary element method were proposed, which allowed to create a mathematical model of the distribution of boron concentration over the thickness of the hardened titanium alloy. The processes of heating by high-frequency currents and due to the preliminary laser treatment of parts were intensified, which allowed to obtain high performance properties of the surface layers with a significant reduction in the duration of treatments. A comparative analysis of the influence of existing and developed hardening treatments on the change in the depth of the layer, the surface hardness and wear resistance of the surface layer of steel 38Ch2MoAl was done. It was established that the developed complex hardening treatment based on the process of diffusion saturation with boron can provide wear resistance of the surface layers at a high level with abrasive wear.

Дисертаційна робота присвячена створенню композитів триботехнічного призначення з підвищеними експлуатаційними властивостями на основі механоактивованих ПТФЕ та наповнювачів різної хімічної природи. Запропоновано підхід підготовки матриці та наповнювачів різної хімічної природи для одержання ПТФЕ-композитів шляхом обґрунтованого вибору співвідношення інгредієнтів та технології їх модифікування. Встановлено оптимальні режими процесу механічної активації матричного ПТФЕ, волокнистих і дисперсних наповнювачів. Вивчено вплив технологічних параметрів процесу механічної активації на структуру, фізико-механічні та триботехнічні властивості ПТФЕ-композиту. З розробленого ПТФЕ-композиту виготовлені поршневі кільця і сальникові ущільнення поршневих компресорів 4ГМ 2,5 У–3,4/2,8–251, які успішно пройшли промислові випробування на ТОВ «Науково-впровадницьке підприємство СумиПластПолімер» і за експлуатаційними характеристиками не поступаються промисловим зразкам.
The thesis is devoted to creation of composites of tribotechnical appointment with the increased operational properties based on mechanically activated polytetrafluoroethylene and fillers of various chemical nature. An approach of preparation of a matrix and fillers of various chemical nature for obtaining PTFE-composites by the reasonable choice of a ratio of ingredients and technology of their modifying is offered. The optimum modes of process of mechanical activation of PTFE-matrix, fibrous and disperse fillers are set. Influence of technological parameters of process of mechanical activation on structure, physical and mechanical and tribotechnical properties of the PTFE-composite is studied. It is shown that under the influence of mechanical activation the ordered spherolitic supramolecular structure of matrix PTFE is formed which is characterized micro- and the nanoscale and leads to an increase in the thermal resistance of a modified polymer on (293–353) K. It is established that mechanical activation does not result in noticeable destruction of polytetrafluoroethylene molecular chain, but there are conformational changes which consist in an increase in concentration of the valent and finite CF2 groups that can lead to enhanced physical, mechanical and service properties of the polymer. It is revealed that the main factors that determine tribotechnical and physical and mechanical properties of PTFE are the time of activation and rotating speed of working organs of a mill. It is mathematically proved the practical experimental mode of mechanical activation at which operational characteristics of matrix PTFE are maximum (n = 9000 min.-1, τ = 5 min.). In comparison with non-activated polymer the level of breaking strength has grown by 2,6 times, relative elongation - by 4,3 times, wear resistances – by 1,86 times. Different technological methods of increasing the adhesive interaction between the ingredients of PTFE-composites are investigated. The prospects of using mechanical activation not only of the matrix but also fillers of various chemical nature for improving of operational characteristics of composites are shown. The determining factor of increase in a complex of operational properties of mechanically activated PTFE-composites is forming spherolitic composite structure under the influence of active particles of disperse layered fillers which playing a role of germs of crystallization and formation on a surface of fibers and coke of the interfacial layer of PTFE which contributes to the emergence of a stable spatial cluster of a filler in volume of a matrix of composition and allows to reach the maximum reinforcing effect, thereby, raising strengthening characteristics of the material and its wear resistance. It is revealed that introduction of a binary filler increases wear resistance of the developed composites by (2,6–4,1) times in comparison with two-component composites. The greatest increase in wear resistance at preservation of high values of physical and mechanical properties of PTFE-composites is watched at synergetic effect of application of mechanical activation of a matrix, fillers, their mixing by two-stage mode and use of a binary filler of various chemical nature. The feature of the developed manufacturing technology of PTFE-composites consists in preliminary separate preparation of a matrix and fillers before their mixing by mechanical activation at various modes of the equipment therefore there is an increase in level of their breaking strength by 1,4 times and wear resistances by (3,7–6,0) times in comparison with industrial analogs that increases durability of work of frictional units of the compressor by (1,8–2,3) times. Piston rings and packing seals of piston-type compressors 4ГМ 2,5 У-3,4/2,8-251 are made of developed PTFE-material that successfully passed industrial tests at LLC «Scientific and innovative enterprise SumyPlastPolymer» and they are not worse than the industry samples. Technological process of PTFE-composite production is developed.
Диссертация посвящена созданию композитов триботехнического назначения с повышенными эксплуатационными свойствами на основе механоактивированных ПТФЭ и наполнителей различной химической природы. Предложен подход подготовки матрицы и наполнителей различной химической природы для получения ПТФЭ-композитов путем обоснованного выбора соотношения ингредиентов и технологии их модифицирования. Установлены оптимальные режимы процесса механической активации матричного ПТФЭ, волокнистых и дисперсных наполнителей. Изучено влияние технологических параметров процесса механической активации на структуру, физико-механические и триботехнические свойства ПТФЭ-композита. Из разработанного ПТФЭ-композита изготовлены поршневые кольца и сальниковые уплотнения поршневых компрессоров 4ГМ 2,5 У–3,4/2,8–251, которые успешно прошли промышленные испытания на ООО «Научно-внедренческое предприятие СумыПластПолимер» и по эксплуатационным характеристикам не уступают промышленным образцам.

碩士
國立臺北科技大學
材料科學與工程研究所
97
An nvestigation on Slag modifier is added to low carbon wear- resistance steels in the high frequency induction furnace melting. Recelently there were two ways to do in the high frequency induction furnace melting. One iscalled SPAL(Surface Protective Air Liquide) procress, the other is Gas Diffuser procress .Generally peaking high frequency induction furnace is only melting but add Slag modifier can dorefining the same as steel making, There has refining procress too, Slag modifier is the same application as E.S.R(Elactroslag relting). The liquid metal can be purifying, It get good mechanical properties. We add Slag modifier some different quantity in the high frequency induction furnace melting to to low carbon wear- resistance steels It not only can increase liquid metal fluidity but also reduce gas hole, inclusion to get good mechanical properties. This is a creative way to do .The benefit is It can help operator simply to do his job also reduce cast cost ,we have done many material test to disscuss for example: the tensile strength test,hardness test,impact test ,S.E.M micrographs,XRD analtsis ect. iffuser),SPAL (Surface protection Air Liquid).

碩士
明志科技大學
化工與材料工程研究所
95
TaN–Cu nanocomposite films were deposited by reactive co-sputtering on Si and tool steel substrates. The films were then annealed using RTA (Rapid Thermal Annealing) at 400 C for 2、4、8 minutes respectively to induce the nucleation and growth of Cu particles in TaN matrix and on film surface. C-AFM (Conductive Atomic Force Microscopy)、SSPM (Scanning Surface Potential Microscopy)and FESEM (Field Emission Scanning Electron Microscopy) were applied to characterize Cu nano-particles emerged on the surface of TaN-Cu thin films. The effect of annealing on anti-wear and anti-bacterial properties of these films was studied. The results reveal that annealing by RTA can cause Cu nano-particles to emerge on the TaN surface. Consequently, hardness and friction coefficients will change, as well as the anti-bacterial behavior.，According to the results TaN-11at%Cu has the best anti-bacterial behavior (reach >99%),While TaN-1.4at% has the highest hardness at 27.5 GPa,after 8-minute annealing。

碩士
國立成功大學
機械工程學系
87
The research on Diamond-Like Carbon (DLC) has found the numerous applications in industry but the research is limited. In this thesis, Gridless Ion Beam Source (GIBS) method is used to deposit various thickness DLC on CR39 plastic lens. The effects of two different thickness of intermediate layer and the addition of SiO2 are investigated. The primary topics on this thesis are as follows: 1. The structure and optical properties of DLC are investigated by Raman Spectrum, X ray Diffractometer (XRD), ellipsometer and visible transmission. 2. The wear test under different operating conditions. 3. The evaluation of adhesion strength by tape pull-off test based on ASTM standard. 4. The humidity durability and salt spray test based on MIL standard. This thesis studies on the relationship among these results. From the analysis of DLC microstructure and the pull-off test, the quality of this DLC film is excellent. The microstructure is amorphous and the graphitization is low. On the optical property, the refraction index is 2.0~2.1 in the visible light area and extinction coefficient is 0.13~0.23 and the transitivity is above 60%. With the addition of SiO2, the films tends to cracking and the adhesion strength, the wear resistance and erosion resistance is reduced. This is contrary to the common belief that the addition of SiO2 is advantageous in adhesion and wear resistance. The film thickness seems to play an important role in these areas. The thicker the film, the wear-resistance is better but the transitivity is reduced. However, the thickness of SiO2 is not arbitrary: only certain thickness ratio with DLC films improves the quality of the overall property. The occurrence of cracks in deposition films will greatly reduced the erosion resistance as well as the wear resistance capability. The adhesion strength is crucial in the evaluation of the deposition quality. For low adhesion strength, the erosion resistance reduced accordingly. The correlation with wear resistance is less obvious. In wear test, the average friction coefficient increases as the load increases; however, the average friction coefficient decreases slightly as the rotation speed increases. For thicker DLC film (above 80nm), the applied load and the rotation speed must exceed certain value to initiate the cracking in the films.

碩士
國立臺灣師範大學
工業教育研究所
88
The main purpose of this research is to investigate the effects of graphite on mechanical properties and wear resistance of castings of Graphite /A390 Al-matrix composite by various amount of reinforcement (3wt%、7wt%、10wt%) after heat treatment. According to the wettability between the surface of graphite and aluminum melt is poor, it is difficult to mix the graphite into aluminum melt directly. Thus, by using cementation process products a copper layer onto the surface of graphite in order to improve the wettability. The experimental results show that can mix graphite into aluminum melt successfully after adding a copper layer on graphite surface. Additionally, the strong shear force by liquid stirring can spread graphite averagely into A390 Al-alloy basement. In Graphite /A390 Al-matrix composites, under increasing quantity of graphite, the hardness tends to increase, the tensile strength tends to decrease ,and weight loss of wearing tends to decrease. By the releasing of graphite and the forming of graphite solid lubrication, Graphite /A390 Al-matrix composites can prevent from sticking phenomenon and serious plough.

碩士
國立臺灣科技大學
機械工程系
92
A7075 aluminum matrix composite billet with different reinforcing particles and different particle sizes were made in this study. Hot extruded process was proceeded at temperature 480℃, then the extrusion products were treated under a T6 aging heat treatment, finally the hardness test and tensile test were carry out under room temperature. For the purpose of investigating the mechanical properties and wear resistance, wear tests under different load were carry out too. The factor that most influence the hardness of composites is the aging heat treatment. Adding nano reinforcing particles can effectively promote the tensile strength and ductility of the composites, but the ductility will decrease with the increase of reinforcement adding quantity and particle size. The wear resistance of A7075 aluminum composite can get obvious improvement via adding SiC reinforcing material, especially under the wear test of light load. When adding micro reinforcing particles and under the test of heavy wear load, large reinforcing particles (102μm) were stripped from the matrix and cause severe wear, but in the case of adding small reinforcing particles (14μm), the particles were removed with matrix and the total wear volume is comparatively small. When adding nano reinforcing particles, the particle size does not seem to affect the wear volume.

碩士
健行科技大學
機械工程系碩士班
106
The diamond cutting line is one of the main consumable elements in the green energy industry of the advanced countries. Diamonds have the advantages of high inertness and high hardness. The surface structure is one of the important factors affecting the material properties. Watts nickel plating was used as electroplating techniques with applying different electroplating conditions such as different current density(0.015386 A/dm2,0.017584 A/dm2,0.019782 A/dm2), diamond powder concentration(3g/L,4g/L), diamond surface coating type (Ti,Ni), electroplating time(15 sec,20 sec), additives(Ethylenediaminetetraacetic acid,EDTA), etc.. Diamond particle size was 6~12µm, and brass-plated steel wire (5cm) was used and other controlled plating techniques to form an excellent nickel-diamond composite coating to improve the corrosion resistance and wear resistance of this material, in order to improve the service life of the diamond cutting wire. In this study, a Potentiostatic and a wet abrasion tester were used to evaluate the corrosion resistance and wear resistance of diamond thin wires under different plating conditions. The optimum conditions were found that the current density was 0.019782 A/dm2, the adding diamond concentration was 4g/L, and the plating time was 20 sec. With the addition of EDTA, the titanium (Ti) diamond thin wire has the best corrosion resistance and wear resistance.

碩士
元智大學
機械工程學系
97
MWCNT (Multi-walled carbon nanotube) have many advantages like excellent mechanical properties, perfect tubular structure, and self-lubricant effect. When MWCNTs are distributed evenly inside the substrate, the mechanical properties of the composite will be reinforced, the friction between two interfaces are reduced, and the wear resistance of materials are enhanced. Many researches focus on the relationship between alignment of MWCNTs and dielectrophoresis. They operated the alignment of MWCNTs by the fixed electrode gap. In this research, we will increase the electrode gap in order to network the MWCNTs and fabricate the MWCNTs composites. Experimental result shows that the aligned MWCNTs would actively enhance the wear resistance and dynamic mechanical properties of composites.

碩士
國立臺灣科技大學
機械工程系
88
The purpose of this study is to evaluate the wear resistance and mechanical behaviors of sintered carbides. In this work, TiC and WC based powder was aided 20% or 30% binders which consist of Mo、Ni and Co in different percentage. After liquid phase sintering, the effects of processes parameters like as particle size、sintering condition、material composition were evaluated by various test rigs. As a result, experiment data show that the particle size of based powder between 0.8 and 4.0 µm can enhance the ratio of bulk density to theoretical density; also, in this powder size range the transverse rupture strength (TRS) of specimen increase with the based powder size. Decreasing the quantity of binder or doping certain Mo powder will increasing the grade of hardness and the ability of wear resistance, but harm for TRS and vise versa. Therefore, molybdenum is one of the main binders of sintering carbides for wear resistance application. According to the test results, the sintering powder consist of 70%WC+10%TiC+15%Ni+5%Mo has the best wear resistance ability and mechanical properties in all testing specimen. Moreover, wear test process with surfaces coating diamondlike carbide (DLC) film counterpart can reduce both wear loss and friction coefficient of these testing pairs.

碩士
國立東華大學
材料科學與工程學系
99
The low density of Al-Si alloy possesses good recycle property, corrosion resistance, high hardness, low thermal expansion and heat-resisting performance. Therefore, the applications of this alloy in the field of vehicle are increasing, for example engine liner of car or motorcycle, gear plate of bicycle. However, the improvement of wear resistance of Al-Si alloy in order to extend their applications, surface treatment is very important issue. This research is focus on the near eutectic composition of Al-12wt%Si alloy. The direct chill casting method is used to cast the hypereutectic Al-Si alloy into 8’ billet. Then the billet is extruded into 5mm thick plate. The metallurgical bonded ceramic coating on this plate is fabricated by micro-arc oxidation (MAO) treatment. The effects of the electrolytic composition adding 4 different contents of Na2SiO3 and/or K2HPO3 will be investigated. To evaluate the microstructures, crystal structure, thickness of the coating layer, interface between the substrate and layer, optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM) will be used. The wear resistance test is performed by using the pin-on disc method with different load and sliding length. Finally, from the results of microstructural evaluation and wear resistance test, this research will find out the optimal condition of MAO for Al-Si alloy, and transfer to industrial application.

碩士
長庚大學
機械工程學系
98
Mg alloy, AZ91D, which has a two-phase structure, was successfully electroplated in an alkaline Cu-plating bath. The Cu-coated Mg alloy specimen was further electroplated in eco-friendly acidic Cu and then trivalent Cr baths to obtain an anti-wear and anti-corrosion Cr/Cu coating. Experimental results show that the wear and corrosion resistance of the Mg alloy specimen was considerably improved by trivalent Cr electrodeposition. The hardness of the as-plated Cr deposit was drastically increased by using reduction-flame heating for 0.5 s. A superior wear and corrosion resistance was obtained when a Cu-coated Mg alloy specimen was electroplated with a trivalent Cr deposit, followed by heating with reduction-flame heating for 0.5 s. The corrosion behavior of Cu-coated and Cr/Cu-coated AZ91D specimens was studied electrochemically in 0.1 M H2SO4 with different NaCl concentrations. The corrosion resistance of Cr/Cu-coated AZ91D decreased with increasing NaCl concentration in 0.1 M H2SO4 solution. After immersion in a 0.1 M H2SO4 with a NaCl-content above 3.5 wt.%, the surface of Cr/Cu-coated AZ91D suffered a few blisters. Cracks through the Cr deposit provided active pathways for corrosion of the Cu and the AZ91D substrate. Formation of blisters on the Cr/Cu-coated AZ91D surface was confirmed based on the results of an open-circuit potential test, which detected an obvious potential drop from noble to active potentials. The above-mentioned results were measured via bonding strength, hardness, wear and corrosion tests.

碩士
健行科技大學
機械工程系碩士班
104
This study using electroless-plating techniques to deposit the Ni-P-Cu/Graphene composite coatings on AA6061 aluminum alloy substrate after pre-treatment including thermal oxidation or anodizing evaluates the structure, mechanical properties of the composite coatings as well as their corrosion and wear resistance in 0.5M H2SO4 solution. The corrosion resistance behavior of the composite coatings was performed by using electrochemical polarization measurements. The surface morphology and elemental analysis and surface hardness of the composite coatings before and after all tests are analyzed by scanning electron microscopy (SEM) and X-ray energy dispersive analyzer (EDS). The surface hardness of the specimens was measured by a Vickers′ micro-hardness tester. It is hoped that the effect of the thermal oxidation or anodizing pre-treatment on the surface structure, corrosion and wear resistance of the composite coatings could be evaluated. The results indicated that AA6061 aluminum alloy after anodizing oxidation increases its surface hardness as well as the electroless Ni-P-Cu/Graphene composite coatings. Moreover, these composite coatings could present the well corrosion and wear protection ability to the aluminum alloy substrate. Because the graphene has a good lubrication ability such that the Ni-P-Cu/Graphene composite coating has the best corrosive wear resistance property especially as the alloy substrate after anodizing pre-treatment.

碩士
國立高雄第一科技大學
機械與自動化工程所
91
Aluminum alloys have been considered to be one of the most versatile useful materials because of their interesting mechanical properties, such as high strength-weightratio, high electrical conductivity, good thermal conductivity, easy to shape, and relatively inexpensive. However, the low hardness, low melting point of such alloys result in poor friction properties and heat resistance. The Co2 laser alloying is one of the efficient method to improve the surface wear resistant.This paper is using CO2 laser alloying Ni-based and Co-based powder on the surface of 6061 Al-Mg-Si alloy and than to discuss the wear resistance property on high temperature. In this study we also will discusses the variation of composition, hardness,and the microstructure throughout the alloying layers after heat treatment. As Experimental result；we can find alloying layer can be divided into four layers, such as surface layer, subsurface layer, middle layer, and interface layer. The main reason to cause the variation of the alloying layer is due to different cooling rate and density. The Ni-based of the surface layer has the Al3Ni oriented microstructure due to rapid fast cooling rate, the subsurface layer has bigger Al3Ni2 dendritic microstructure, and the middle layer has Al-Ni-Cr amorphous microstructure. The Co-based of the surface layer has the Al9Co2 microstructure, the subsurface layer is Al13Co4 microstructure, and the middle layer is strip-like Al5Co2 microstructure. About the hardness test, the surface layer and the interface layer of Ni-based and Co-based after the laser alloying are influenced by effect of substrate.So the hardness is not increasing obviously. The middle layer is belonging to amorphous structure, and its hardness is 20 times than substrate. The life of the Ni-based and Co-based laser alloying treatment is 3 times as the based material after the wear resistance test under the 250 ℃. After the heat treatment, the α-Al of the alloying surface layer appears the nodulizing precipitation, the hardness is twice than original one. It can also improve the hardness gradient of the Ni-based alloying layers, and decrease the stress concentration. But the wear resistance property does not increase obviously since decreasing of the hardness in the middle layer. The Co-based alloying has better heat-resistance property.After heat treatment, the hardness of surface layer alloying increases. And the milled layer alloying is hard to solution precipitating Al9Co2 microstructure, it can keep the original hardness（Hv501038）. So the Co-based heat-treatment sample alloying has the best wear resistance during high temperature (200℃) of this research.

博士
國立成功大學
材料科學及工程學系
104
In this study, a new type and two-step SIMA process for Al-Mg-Si alloy were used. And the microstructural characteristics, high-temperture formability, mechanical properties and erosion properties were investigated. The high-hardness globular grain boundaries are formed by eutectic phases. This new type SIMA process was poved that it can decrease high-temperature compressive resistance and improve ability of metal flowing at high temperature. After SIMA forming process, the mechanical properties of materials can compete with common artificial aged materials. In addition, the oblique erosion resistance of Al-Mg-Si alloys also can be promoted by this new type SIMA process. All the results show that this SIMA process is a potential process.