Dissertations / Theses on the topic 'Alloy additive'
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Palanivel, Sivanesh. "Thermomechanical Processing, Additive Manufacturing and Alloy Design of High Strength Mg Alloys." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc849628/.
Full textPuleo, Shawn Michael. "Additive Friction Stir Manufacturing of 7055 Aluminum Alloy." ScholarWorks@UNO, 2016. http://scholarworks.uno.edu/honors_theses/75.
Full textKumara, Chamara. "Microstructure Modelling of Additive Manufacturing of Alloy 718." Licentiate thesis, Högskolan Väst, Avdelningen för avverkande och additativa tillverkningsprocesser (AAT), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-13197.
Full textCao, Pengcheng. "Characterization of Laser Deposited Alloy 718." Thesis, KTH, Materialvetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-182603.
Full textWang, Xueyuan. "Predicting fatigue crack growth life in additive manufactured titanium alloy." Thesis, Coventry University, 2016. http://curve.coventry.ac.uk/open/items/723714e9-2b61-4464-b6b9-a9c05a0a74b0/1.
Full textMikler, Calvin. "Laser Additive Manufacturing of Magnetic Materials." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc1011873/.
Full textAboulkhair, Nesma T. "Additive manufacture of an aluminium alloy : processing, microstructure, and mechanical properties." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/31152/.
Full textGavelius, Marianne, and Karin Andersson. "Surface Treatment for Additive Manufactured Aluminum Alloys." Thesis, Linköpings universitet, Molekylär ytfysik och nanovetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-169027.
Full textSheridan, Luke Charles. "An Adapted Approach to ProcessMapping Across Alloy Systems and Additive Manufacturing Processes." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1471861921.
Full textTollander, Sofia, and Mona Kouach. "Repeatability of Additive Manufactured Parts." Thesis, KTH, Materialvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-209804.
Full textSaab Surveillance i Järfä̈lla konstruerar komplexa försvarsprodukter som till exempel radarsystem. Additiv tillverkning i metall möjliggör tillverkning av produkter med hög komplexitet, men då tillverkningsprocessen är relativt ny i industrin finns det en stor osäkerhet kring processen. Syftet med detta kandidatexamensarbete var att få en bättre förståelse för repeterbarheten hos additivt tillverkade delar samt att jämföra additivt tillverkade provstavar konstruerade i två olika riktningar, horisontellt och vertikalt, med svarvade provstavar med hjälp av ett vibrationstest. Vibrationstestet genomfördes för att simulera den operativa miljön där de additivt tillverkade detaljerna skulle kunna implementeras i framtiden. Innan vibrationstestet kunde utföras simulerades provstavarnas design i en mjukvara för 3D-modellering. En finit element-analys utfördes även fö̈r att få en egenfrekvens inom intervallet 100 - 200 Hz och en maximal böjspänning mellan 60 - 80 MPa i anvisningen på provstaven. Slutsatsen drogs att de traditionellt bearbetade stavarna hade den högsta repeterbarheten. De horisontellt additivt tillverkade stavarna hade högre repeterbarhet än de vertikalt additivt tillverkade stavarna, men att de vertikalt additivt tillverkade stavarna hade ett längre utmattningsliv. Det kunde även konstateras att fler studier inom ämnet behövs för att kunna säkerställa repeterbarheten hos additivt tillverkade delar utan att behöva kompromissa med hållfastheten.
Calvert, Jacob Rollie. "Microstructure and Mechanical Properties of WE43 Alloy Produced Via Additive Friction Stir Technology." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/55816.
Full textMaster of Science
Xu, Jinghao. "Alloy Design and Characterization of γ′ Strengthened Nickel-based Superalloys for Additive Manufacturing." Licentiate thesis, Linköpings universitet, Konstruktionsmaterial, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-173042.
Full textAdditional funding agencies: Agora Materiae Graduate School for multidisiplinary PhD students at Linköping University, and Stiftelsen Axel Hultgren.
Hasting, William. "Geometric Effects of Free-Floating Technique on Alloy 718 Parts Produced via Laser-Powder Bed Fusion." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1613751580039925.
Full textBalachandramurthi, Arun Ramanathan. "Fatigue Properties of Additively Manufactured Alloy 718." Licentiate thesis, Högskolan Väst, Avdelningen för avverkande och additativa tillverkningsprocesser (AAT), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-13186.
Full textAntonysamy, Alphons Anandaraj. "Microstructure, texture and mechanical property evolution during additive manufacturing of Ti6Al4V alloy for aerospace applications." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/microstructure-texture-and-mechanical-property-evolution-during-additive-manufacturing-of-ti6al4v-alloy-for-aerospace-applications(03c4d403-822a-4bfd-a0f8-ef49eb65e7a0).html.
Full textSegerstark, Andreas. "Additive Manufacturing using Alloy 718 Powder : Influence of Laser Metal Deposition Process Parameters on Microstructural Characteristics." Licentiate thesis, Högskolan Väst, Avd för tillverkningsprocesser, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-8796.
Full textGustavsson, Bengt. "Effect of Beam Scan Length on Microstructure Characteristics of EBM Manufactured Alloy 718." Thesis, KTH, Materialvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-225416.
Full textGaly, Cassiopee. "Etude des interactions matériau/procédé en vue d'une optimisation des conditions opératoires du procédé de fabrication additive SLM sur des alliages d'aluminium pour des applications aéronautiques." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0106/document.
Full textInterest in selective laser melting (SLM) has been growing in recent years, particularly with regard to the production of metal parts.The low density of aluminum alloys, combined with the possible design optimization enabled by additive manufacturing processes,ensures a significant decrease in the mass of structures which is very interesting for manufacturers in the automotive and aerospaceindustries. However, it is difficult to control the final properties of aluminum parts manufactured by SLM because many defects, suchas porosity, hot cracking, and surface roughness, are generated during the process. To better understand how to optimize theperformance of SLM aluminium parts, several studies were conducted during this work: An identification and selection of characterization methods well-adapted to the specificities of metallic materials developedby powder bed additive manufacturing processes was established. For instance, the comparison of different methods ofdetermining the relative density of parts showed the advantages and disadvantages of each of the techniques; A study of the SLM machine highlighted the influence of various factors (gas flow, positions of specimens on the constructionplate, or methods of depositing the powder) on the final properties of the produced parts. These elements have an impacton the density of the parts, their surface properties, and their mechanical properties. We found that the positioning of a pieceon the tray is a critical step in the preparation of a build that is not to be neglected; Parametric studies carried out on two types of aluminum alloys—AlSi7Mg0,6 and AM205—have shown that the chemicalcomposition of the aluminum alloy used has a significant influence on the set of operating parameters required tomanufacture an acceptable aluminum alloy part. The energy density, ψ, which is the ratio of the laser power to the productof the lasing speed, the hatching distance, and the layer thickness, is conventionally used for the optimization of the operatingconditions in SLM. Our experimental studies performed at different scales (1D and 3D) have shown the limits of this criterion.The combination of these results with the numerical simulation of the lasing of a single powder bead served as a basis forthe definition of an initial model, the final objective of which will be to optimize the choice of manufacturing parameters
Somasundaram, Aruneshwar. "Characterization of Microstructure and Mechanical Properties of Laser Powder Bed Fusion Processed Inconel 625 Alloy." University of Cincinnati / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1627658971938259.
Full textWalker, Joseph R. "Multi-Sensor Approach to Determine the Effect of Geometry on Microstructure in Additive Manufacturing." Wright State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=wright1558900598369986.
Full textAnderson, Walter. "Development of an Intervertebral Cage Using Additive Manufacturingwith Embedded NiTi Hinges for a Minimally Invasive Deployment." University of Toledo / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1368182356.
Full textMohandass, Venkataramanan. "EB-PBF additive manufacturing of Alloy 718 : Effect of shot peening on surface characteristics and high temperature corrosion performance." Thesis, Högskolan Väst, Avdelningen för Industriell ekonomi, Elektro- och Maskinteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-14352.
Full textTatman, Eric-Paul Daniel. "The Characterization and Fatigue Life Impact from Surface Roughness on Structurally Relevant Features Produced Using Additive Manufacturing." Wright State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=wright1564754673356237.
Full textTaheri, Andani Mohsen. "Modeling, Simulation, Additive Manufacturing, and Experimental Evaluation of Solid and Porous NiTi." University of Toledo / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1438888243.
Full textSojiphan, Kittichai. "Effects of Very High Power Ultrasonic Additive Manufacturing Process Parameters on Hardness, Microstructure, and Texture of Aluminum 3003-H18 Alloy." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1418667794.
Full textCaputo, Matthew P. "4-Dimensional Printing and Characterization of Net-Shaped Porous Parts Made from Magnetic Ni-Mn-Ga Shape Memory Alloy Powders." Youngstown State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1525436335401265.
Full textSegerstark, Andreas. "Laser Metal Deposition using Alloy 718 Powder : Influence of Process Parameters on Material Characteristics." Doctoral thesis, Högskolan Väst, Avdelningen för svetsteknologi (SV), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-11842.
Full textGoel, Sneha. "Post-treatment of Alloy 718 produced by electron beam melting." Licentiate thesis, Högskolan Väst, Avdelningen för avverkande och additativa tillverkningsprocesser (AAT), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-13547.
Full textArticles submitted to journals and unpublished manuscripts are not included in this registration
Nilsson, Erik, and Daniel Johansson. "Testing and evaluation of component made using electron beam melting and Alloy 718 powder." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-35566.
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Makiewicz, Kurt Timothy. "Development of Simultaneous Transformation Kinetics Microstructure Model with Application to Laser Metal Deposited Ti-6Al-4V and Alloy 718." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1366023857.
Full textMeisel, Nicholas Alexander. "Design for Additive Manufacturing Considerations for Self-Actuating Compliant Mechanisms Created via Multi-Material PolyJet 3D Printing." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/54033.
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Kusuma, Chandrakanth. "The Effect of Laser Power and Scan Speed on Melt Pool Characteristics of Pure Titanium and Ti-6Al-4V alloy for Selective Laser Melting." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1464271345.
Full textMyers, Eric J. "Finite Element Modeling (FEM) of Porous Additively Manufactured Ferromagnetic Shape Memory Alloy Using Scanning Electron Micrograph (SEM) Based Geometries." Youngstown State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ysu149399154152881.
Full textBradford-Vialva, Robyn L. "Development of a Metal-Metal Powder Formulations Approach for Direct Metal Laser Melting of High-Strength Aluminum Alloys." University of Dayton / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1620259752540201.
Full textHuser, Gautier. "Etude et sélection d’alliages à composition complexe sans cobalt à finalité tribologique." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPAST051.
Full textCurrently, attempts are made to develop hardfacing cobalt-free alloys for coating the contact areas of moving parts of nuclear installations. In fact, under neutron flux, cobalt 59 is activated into cobalt 60, a highly radioactive isotope. Consequently, the coating debris generated by friction are likely to contaminate parts of the installation. Existing cobalt-free hardfacing alloys, nickel or iron bases, do not exhibit tribological properties competing with those of stellite®, a commonly used hardfacing cobalt base alloy. HEA (High Entropy Alloy) and CCA (Complex Concentration Alloy) may be good candidates. Indeed, compare to conventional alloys, they show vast composition domain giving access to a large range of properties. After an initial selection of elements, the phases of selected alloys were calculated by CALPHAD software (CALculation of PHAse Diagram). The compositions favoring the presence of hard intermetallic phases beneficial to tribological behavior were selected. Then several alloys were fabricated using different processes. From microstructural and tribological characterizations, one composition has been selected as the best potential cobalt-free hardfacing alloy candidate. Coatings of this composition were then fabricated by DLD (Direct Laser Deposition) and HIP (Hot Isostatic Pressing). Their microstructure and tribological behavior were measured and compared to those of stellite ®
Hazlehurst, Kevin Brian. "The adoption of laser melting technology for the manufacture of functionally graded cobalt chrome alloy femoral stems." Thesis, University of Wolverhampton, 2014. http://hdl.handle.net/2436/332114.
Full textNastic, Aleksandra. "Repair of Aluminum Alloy Aerospace Components and Cold Gas Dynamic Spray Flow Distribution Study." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32998.
Full textSheridan, Luke C. "Primary Processing Parameters and Their Influence on Porosity and Fatigue Life of Additively Manufactured Alloy 718." Wright State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=wright1588254461821575.
Full textGwalani, Bharat. "Developing Precipitation Hardenable High Entropy Alloys." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc1011755/.
Full textWhip, Bo Ryan. "Effect of Process Parameters on the Surface Roughness and Mechanical Performance of Additively Manufactured Alloy 718." Wright State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=wright1526993831680976.
Full textKarimi, Neghlani Paria. "Electron beam melting of Alloy 718 : Influence of process parameters on the microstructure." Licentiate thesis, Högskolan Väst, Avdelningen för avverkande och additativa tillverkningsprocesser (AAT), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-13140.
Full textAdegoke, Olutayo. "Processability of Laser Powder Bed Fusion of Alloy 247LC : Influence of process parameters on microstructure and defects." Licentiate thesis, Högskolan Väst, Avdelningen för avverkande och additativa tillverkningsprocesser (AAT), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-16114.
Full textDokoupil, Filip. "Zpracování slitiny 2618 pomocí technologie selective laser melting." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231934.
Full textColman, Bruno Fontoura da Silva. "Projeto de prótese de disco intervertebral de Ti-6Al-4V entre L4/L3." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/153841.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Esse trabalho tem a finalidade de projetar, com base em levantamento bibliográfico, uma prótese de disco intervertebral de Ti6Al4V pelo processo DMLS. Os sistemas de imagem de tomografias computadorizadas e ressonâncias magnéticas trabalham de maneira semelhante. Imagens em 3D de dados dos pacientes são construídas através da combinação de fatias 2D tomadas a partir de sistemas de sensores e da interpolação entre eles. A distância entre as fatias desses sistemas de imagens é grosseira comparada com a tecnologia da manufatura aditiva, portanto, esses processos combinam as imagens das fatias dentro de um software para criar um modelo 3D sobrepondo camadas, devido a essa sinergia entre os dois tipos de sistema, pesquisadores de todo o mundo tentam melhorar e inventar próteses para substituir o disco intervertebral através da ciência. Os resultados mostraram que a fabricação de uma prótese de disco com junta esférica pelo processo de manufatura aditiva é viável, porém nos segmentos menores, como na cervical ainda são difíceis de produzir devido à altura do disco intervertebral e ao limite da dimensão das camadas da manufatura aditiva, que atualmente estão por volta dos 20μm, por isso requerem tratamentos superficiais após sua fabricação. Espera-se que este trabalho possa ajudar futuros pesquisadores da área de biomecânica da coluna vertebral.
This work has the purpose of designing, based on a bibliographical survey, an intervertebral disc prosthesis of Ti6Al4V by the DMLS process. Computed tomography (CT) imaging systems and MRIs work similarly. 3D images of patients data are constructed by combining 2D slices taken from sensor systems and interpolating between them. The distance between the slices of these imaging systems is rough compared to the additive manufacturing technology, so these processes combine the slice images within a software to create a 3D model overlapping layers because of this synergy between the two system types, researchers around the world try to improve and devise prostheses to replace the intervertebral disc through science. The results showed that the manufacture of a disc prosthesis with spherical joint by the additive manufacturing process is feasible, but in the smaller segments, such as in the cervical still difficult to produce due to the height of the intervertebral disc and to the limit of the size of the layers of the manufacture additives, which are currently around 20μm, so they require surface treatments after their manufacture. It is hoped that this work may help future researchers in the area of spinal biomechanics.
CAPES - PROPG
Ковба, Анастасія Миколаївна. "Розроблення екструдера для модернізації установки виробництва полімерних гранул." Master's thesis, КПІ ім. Ігоря Сікорського, 2019. https://ela.kpi.ua/handle/123456789/31552.
Full textThe explanatory note consists of an introduction, eight sections, conclusions and a list of links of 35 titles. The total volume of the note is 198 pages, including 133 pages of the main text, 47 figures, 50 tables. The purpose of the master's thesis is to design a cascade disk-gear extruder for the installation of production of polymer granules. The note contains a description of the technological process, the choice of the type of apparatus, their place in the technological scheme, the technical characteristics of the devices, the justification of the choice of designs of the designed devices and the principle of operation of their basic assembly units and parts, comparison of the main indicators of the developed design of the devices with analogues, patent study of the designs of the devices . Measures on safety, installation and operation recommendations are given. The installation was modernized and a startup project was developed. The calculations confirming the efficiency and reliability of the designs of the evaporator and the separator were carried out. The level of standardization and unification is determined. An automatic process control scheme has been developed.
Цель магистерской диссертации - проектирование каскадного дисково-шестеренного экструдера для установки производства полимерных гранул. Записка содержит описание технологического процесса, выбор типа аппарата, их место в технологической схеме, техническую характеристику аппаратов, обоснование выбора конструкций аппаратов, проектируемых и принцип действия их основных сборочных единиц и деталей, сравнение основных показателей разработанной конструкции аппаратов с аналогами, патентное исследование конструкций аппаратов . Приведены мероприятия по охране труда, рекомендации по монтажу и эксплуатации. Проведена модернизация установки и разработано стартап проект. Проведены расчеты, подтверждающие работоспособность и надежность конструкций испарительного аппарата и сепаратора. Определен уровень стандартизации и унификации. Разработан автоматическую схему управлением процессом.
Wahman, Clarence. "Corrosion of additively manufactured magnesium alloy WE43 : An investigation in microstructure and corrosion properties of as built samples manufactured with Powder Bed Fusion-Laser Beam." Thesis, Uppsala universitet, Tillämpad materialvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-448525.
Full textKuntz, Sarah Louise. "Feasibility of Attaining Fully Equiaxed Microstructure through Process Variable Control for Additive Manufacturing of Ti-6Al-4V." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1464557846.
Full textDomfang, Ngnekou Julius-Noël. "Étude expérimentale de la tenue en fatigue de l’alliage AlSi10Mg élaboré par fusion laser de lit de poudre Influence of as-built surface and heat treatment on the fatigue resistance of Additively Layer Manufacturing (ALM) AlSi10Mg alloy Fatigue resistance of selectively laser melted aluminum alloy under T6 heat treatment Fatigue properties of AlSi10Mg produced by Additive Layer Manufacturing." Thesis, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2019. http://www.theses.fr/2019ESMA0015.
Full textThis work shows the impact of defects and microstructure on the fatigue limit of AlSi10Mg produced by Additive Layer Manufacturing (ALM). Samples are produced according to three orientations with respect to the construction plate (0 °, 45 ° and 90 °); the studied surfaces are machined or left as-built (AB) in the gauge section. The specimens are studied with or without T6 heat treatment. The study surfaces are machined or as built. Some specimens are subjected to T6 heat treatment. Before any others study, the material is characterized in connection with the process parameters through several techniques (microscopes and 3D X-ray microtomography). Regarding the fatigue, the S-N curves are established before and after T6, mainly at R = -1 under uniaxial loading. For all the fatigue test specimens, fracture surfaces analysis shows that it is always a defect that cause fatigue failure. Thus, a criterion is applied to define these critical defects (type, size morphology and position) and the fatigue limit is analyzed through the Kitagawa type diagrams. The role of the building direction on the fatigue strength is studied, before and after T6 heat treatment, for both machined and as-built surfaces. For this purpose, a sketch based on the characteristic grain size is proposed to explain post-T6 orientation effects. The contribution of the precipitation structure is also studied; as well as the role of defects (type, size, morphology and position) on the fatigue limit at different microstructural states: before and after T6. In order to understand the surface fatigue damage mechanisms, the replica method is used on a polished specimen. In this context, a propagation law of natural cracks, that is to say due to a defect inherited from the process, is identified. It makes it possible to separate the initiation and propagation phases, thus feeding the discussions on the phenomena of priming in the presence of defects. In addition, some fatigue criteria are also discussed and the Defect Stress Gradient (DSG) approach is adapted to the studied material, by taking into account the size of the crystallographic grains. In the specific case of specimens with as-built useful sections, the role of the process of suppression of the building supports on the initiation of fatigue cracks is studied; the definition of the concept of defect size in the presence of roughness, at the scale of the surface undulation, is discussed. Knowing that initiation can occurs on a surface undulation or on an isolated defect (porosity or lack-of-fusion), an experimental method is proposed to analyze the competition between these factors. In a context of industrial development, the influence on the fatigue limit of the process parameters, related to the laser (scanning speed, power and hatching distance), or powder bed (chemical composition, particle size, bed thickness) is studied, in order to feed the discussions towards the process optimization regarding the fatigue strength
Fischer, Marie. "Élaboration in situ d’alliages de titane et de structures architecturées par fabrication additive : application aux dispositifs médicaux implantables." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0257/document.
Full textThe initial problematic arises from the fact that implant failure is often caused by a mismatch between the elastic properties of the bone and those of the implant. Nowadays, an increasing interest is given to this mechanical biocompatibility and led to the development of β-metastable titanium alloys that possess low Young’s modulus, about half that of the conventionally used Ti-6Al-4V alloy. Moreover, lattice structures are currently being the subject of many investigations with the aim of achieving low Young’s modulus and high strength. Their fabrication, with accurate control over the architecture, is made possible thanks to additive manufacturing processes and the several possibilities they offer: design freedom, reduced material usage rate, complex shapes, mass customisation... The present work focuses on the implementation of low modulus titanium alloy Ti-26Nb(at.%) by the means of selective laser melting. An in situ elaboration strategy, based on a mixture of elemental powders, is explored in order to allow potential composition adjustments and to overcome the unavailability of titanium alloy powders. The approach is carried out using two distinct powder morphologies, spherical and irregular. The effects of the numerous parameters of the process (laser power, speed, scanning strategy...) on homogeneity and porosity of the manufactured parts is quantified. A homogeneous alloy can be obtained subject to the use of suitable energy density levels and powder size distributions that take into account the respective fusion temperatures of both elements. Microstructure characterisation highlights a pronounced texture resulting from the scanning strategy. The elaborated samples display a low Young’s modulus associated with a high strength, and hence a favourable strength to elastic modulus ratio compared to the reference cast alloy. Furthermore, an optimization algorithm is developed and allows controlling the mechanical properties of a lattice structure with its geometrical parameters (radius, length and orientation of struts). The combined use of this low Young’s modulus titanium alloy with a lattice structure developed through this algorithm was applied to the design of a total hip prosthesis that was subjected to finite element simulations. Stress-shielding evaluation shows that, compared to a solid design, this kind of prosthesis permits to reduce stress-shielding significantly. By getting closer to a physiological model, this prosthesis can be qualified as “biomimetic” in terms of mechanical behaviour
Alberani, Marco. "Stabilità ad alta temperatura delle leghe ad alta entropia: effetti della tecnologia di produzione." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21040/.
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