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Artykuły w czasopismach na temat "Intermetallic-Intermetallic eutectic composite alloy"
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Piątkowski, Jarosław, i Robert Wieszała. "Crystallization and Structure of AlSi10Mg0.5Mn0.5 Alloy with Dispersion Strengthening with Al–FexAly–SiC Phases". Metals 9, nr 8 (8.08.2019): 865. http://dx.doi.org/10.3390/met9080865.
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The paper characterizes a composite with dispersion phases cast via the use of stir casting method on an aluminum matrix. A mixture of aluminum with FexAly and SiC powders was achieved in the process of mechanical alloying and self-propagating high temperature synthesis (ASHS). Chemical composition of agglomerates was chosen in such a way that the strengthening components made up 25% of the mass of the AlSi10Mg0.5Mn0.6 (EN AC-43400) alloy matrix. The characteristic temperatures of crystallization of the tested alloy were measured by thermal analysis ATD (analysis thermal derivative). A change of chemical and phase composition was confirmed in the elements of the intermetallic phase FeAl in the aluminum matrix. A silumin casting structure was achieved, with the matrix including micro-areas of ceramic phases and intermetallic phases, which are characteristic for hybrid strengthening. A refinement of dendrites in solid solution α was found, together with a transition from a binary plate eutectic composition α(Al) + β(Si) into modified eutectic composition.
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Huang, Her-Yueh, Chung-Wei Yang i Yu-Chang Peng. "Effects on the microstructure and mechanical properties of Sn-0.7Cu lead-free solder with the addition of a small amount of magnesium". Science and Engineering of Composite Materials 23, nr 6 (1.11.2016): 641–47. http://dx.doi.org/10.1515/secm-2014-0130.
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AbstractThe influence of a small amount of magnesium (only 0.01 wt.%) added to the Sn-0.7Cu solder alloy during the aging process of microstructural evolution is studied along with the mechanical properties of the alloy. The experimental results indicate that the addition of magnesium decreases the tensile strength of the solders but improves their elongation. The solidification structure of eutectic Sn-0.7Cu consists of β-Sn, and the eutectic structure, which has extremely fine intermetallic nodules, Cu6Sn5, is located in the interdendritic region. When the magnesium is added to the Sn-0.7Cu alloy, the Sn dendrites become slightly coarser; in comparison, the melting point of the Sn-0.7Cu-0.01Mg alloy decreased by 2°C for the differential scanning calorimetry results of bulk alloy samples. Sn-0.7Cu-0.01Mg exhibits the lowest contact angles and the widest spreading areas. After aging, the Sn-0.7Cu and Sn-0.7Cu-0.01Mg solders show significant changes in strength, mainly because of the obvious increase in the thickness of the Cu6Sn5 intermetallic layer.
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Tanaka, Yasuhiko, Takeshi Goto i Yoshimi Watanabe. "Graded Microstructure at Fiber / Copper Matrix Interface in FRM Fabricated by the Reaction at Narrow Holes Method". Materials Science Forum 492-493 (sierpień 2005): 737–42. http://dx.doi.org/10.4028/www.scientific.net/msf.492-493.737.
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The reaction at narrow holes method (RANH method) has been proposed for fabricating fiber reinforced metal (FRM), such as an intermetallic compound fiber / metal matrix composite. This study clarifies a microstructure at a fiber / metal matrix interface of FRM fabricated by using a combination of pure-copper and pure-aluminum in the RANH method. Pure-aluminum fiber was inserted into a narrow hole drilled in the copper matrix. The assembly comprising the pure-aluminum fiber and the pure-copper matrix was heated to a temperature greater than eutectic temperature of the copper-aluminum binary alloy. A molten aluminum reacted with copper to form an annular reacted region consisting of g1 intermetallic compound in a single phase near the edge of the narrow hole. The g1 intermetallic compound has very high hardness on the order of 800-900 HV. The annular reacted region may have a high tensile strength and may work as a reinforcing metal fiber in FRM.
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Fathy, N. "Interfacial Microstructure and Bonding Area of Sn-based Alloy-GG25 Gray Iron Bimetallic Material Using Flux, Sn, and Sn-Zn Interlayer Compound Casting". Engineering, Technology & Applied Science Research 12, nr 2 (9.04.2022): 8416–20. http://dx.doi.org/10.48084/etasr.4804.
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A bimetallic casting consisting of GG25 gray iron substrate and Sn-based alloy using the liquid-solid technique has been studied in this paper. Three different pretreatment processes of gray iron surface substrates including flux only, flux and Sn powder, and flux and Sn-8.8% Zn powder eutectic alloy surface treatment were adopted for the aim of improving the quality of tinning, the interfacial structure, and the bonding area of the Sn-based alloy/gray iron bimetallic composite in order to promote the bonding quality of bimetallic castings. Microstructure characterization on the bonding interface was conducted. The novel tinning material for gray cast iron substrate comprising of Sn-8.8% Zn eutectic alloy powder in combination with flux interlayer improved the bonding area, the interfacial bimetal structure, and the shear stress. This improvement is due to the higher interface reaction of Zn with Fe that leads to the formation of a very thin layer of Fe-Zn and Fe-Sn intermetallic phases.
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Zykova, Anna, Aleksandra Nikolaeva, Aleksandr Panfilov, Andrey Vorontsov, Alisa Nikonenko, Artem Dobrovolsky, Andrey Chumaevskii i in. "Microstructures and Phases in Electron Beam Additively Manufactured Ti-Al-Mo-Z-V/CuAl9Mn2 Alloy". Materials 16, nr 12 (9.06.2023): 4279. http://dx.doi.org/10.3390/ma16124279.
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Electron beam additive manufacturing from dissimilar metal wires was used to intermix 5, 10 and 15 vol.% of Ti-Al-Mo-Z-V titanium alloy with CuAl9Mn2 bronze on a stainless steel substrate. The resulting alloys were subjected to investigations into their microstructural, phase and mechanical characteristics. It was shown that different microstructures were formed in an alloy containing 5 vol.% titanium alloy, as well as others containing 10 and 15 vol.%. The first was characterized by structural components such as solid solution, eutectic intermetallic compound TiCu2Al and coarse grains of γ1-Al4Cu9. It had enhanced strength and demonstrated steady oxidation wear in sliding tests. The other two alloys also contained large flower-like Ti(Cu,Al)2 dendrites that appeared due to the thermal decomposition of γ1-Al4Cu9. This structural transformation resulted in catastrophic embrittlement of the composite and changing of wear mechanism from oxidative to abrasive.
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Wloch, G., T. Skrzekut, J. Sobota, A. Woznicki i L. Błaż. "Silver Matrix Composite Reinforced by Aluminium-Silver Intermetallic Phases". Archives of Metallurgy and Materials 62, nr 1 (1.03.2017): 427–34. http://dx.doi.org/10.1515/amm-2017-0066.
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AbstractSilver and aluminum powders (82 mass % Ag and 18 mass % Al) were mixed and hot extruded at 673 K with extrusion ratio λ = 25. Performed X-ray diffraction analysis of as extruded rod revealed the development of Ag3Al and Ag2Al-type intermetallic phases. Structural observations and both chemical and diffraction analysis of structural components confirmed the growth of mentioned phases in the vicinity of elementary Al and Ag granules. No pores or voids were observed in the material. Mechanical properties of the composite, UTS = 490MPa, YS = 440 MPa, HV2 = 136, were relatively high if compared to commercial Ag and Cu products. Hot compression tests pointed to the good hot workability of the composite at deformation temperature range 473 K - 773 K.The differential scanning calorimetry tests were performed in order to estimate structural processes during heating of Ag/Al composite that lead to thermodynamically stable liquid state. It was found that characteristic temperature of three endothermic peaks correspond to (1) peritectoid transformation μ-Ag3Al → ζ-Ag2Al + (Ag), (2) the eutectic melting ζ-Ag2Al + (Al) → L, (3) melting of the ζ-Ag2Al phase.The Vickers hardness of the samples annealed at 673 K, for the time range up to 6900 minutes, was also determined. It was concluded that mutual diffusion of elements between Ag and Al granules and the growth of μ-Ag3Al and ζ-Ag2Al grains during annealing at 673 K result in a slight hardening of the composite.
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Kim, Won Yong, Han Sol Kim, Shae K. Kim, Tae Yeub Ra i Mok Soon Kim. "Effect of Ternary Alloying Elements on Microstructure and Mechanical Property of Nb-Si Based Refractory Intermetallic Alloy". Materials Science Forum 486-487 (czerwiec 2005): 342–45. http://dx.doi.org/10.4028/www.scientific.net/msf.486-487.342.
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Microstructure and mechanical property at room temperature and at 1773 K of Nb-Si based refractory intermetallic alloys were investigated in terms of compression and fracture toughness test. Mo and V were chosen as ternary alloying elements because of their high melting points, atomic sizes smaller than Nb. Both ternary alloying elements were found to have a significant role in modifying the microstructure from dispersed structure to eutectic-like structure in Nb solid solution/Nb5Si3 intermetallic composites. The 0.2% offset yield strength at room temperature increased with increasing content of ternary elements in Nb solid solution and volume fraction of Nb5Si3. At 1773 K, Mo addition has a positive role in increasing the yield strength. On the other hand, V addition has a role in decreasing the yield strength. The fracture toughness of ternary alloys was superior to binary alloys. Details will be discussed in correlation with ternary alloying, volume fraction of constituent phase, and the microstructure.
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Konieczny, Marek. "Mechanical properties and failure analysis of laminated magnesium-intermetallic composites". AIMS Materials Science 9, nr 4 (2022): 572–83. http://dx.doi.org/10.3934/matersci.2022034.
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<abstract> <p>Laminated Mg-intermetallic composites were successfully fabricated by reaction synthesis in vacuum using 1 mm thick magnesium sheets and 0.25 mm thick copper foils. The final microstructure consisted of alternating layers of a hypoeutectic alloy containing crystals of CuMg<sub>2</sub> and eutectic mixture of CuMg<sub>2</sub> and solid solution of copper in magnesium and unreacted magnesium. The mechanical properties and fracture behavior of the fabricated composites were examined under different loading directions through compression, three-point bending and impact tests. The results indicated that the composites exhibited anisotropic features. The specimens compressed in the parallel direction failed by cracking along the layers of intermetallics and buckling of magnesium layers. The specimens compressed in the perpendicular direction failed by transverse cracking in the intermetallic layers and fallowing catastrophic cracking inclined about 45° to the interface of both intermetallic and magnesium layers. The flexural strength of the composites was higher in perpendicular than in parallel direction. When the load parallel to the layers was applied, the failure occurred by cleavage mode showing limited plastic deformation. When the load perpendicular to the layers was applied, the failure occurred by transverse cracking of the intermetallic layers and gradual cracking of the Mg layers. The Charpy-tested samples showed the same fracture behavior as the bend-tested specimens, which indicated that the same mechanisms operated at both high impact rate and low bending-test rate.</p> </abstract>
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Sutliff, J. A., B. P. Bewlay, G. A. Henshall i M. J. Strum. "Facet crystallography of fractured V(2.7 wt% Si) solid solution". Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994): 622–23. http://dx.doi.org/10.1017/s0424820100170840.
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V-Si binary alloys have been investigated as model high temperature alloys. Alloys with compositions between ~4 and 11 wt% Si can be fabricated as in-situ composites composed of the intermetallic V3Si phase and the V(Si) solid solution phase with a eutectic temperature of ~1870°C. The V(Si) phase is thought to be a ductile phase which provides toughness to the composite. We have previously reported on the fracture toughness of V-Si alloys.In this paper we present results on the fracture surface fractography and fracture facet crystallography of an arc-melted V(2.7 wt% Si) solid solution alloy fractured in bending. Figure 1 is a low magnification SEM micrograph of the surface of one half of a fractured bend bar. Many macroscopically flat facets can be seen and those for which crystallographic analysis was done have been labeled. Actually, the macro-facet surface as seen at higher magnification exhibits significant morphological structure, as can be observed in Figure 2 which shows detail of the facet labeled k.
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Касумов, Юрий Надирович, Артур Рубенович Манукянц, Виктор Адыгеевич Созаев i Борис Магометович Хуболов. "PHASE FORMATION IN CONTACT LAYERS DURING CONTACT MELTING OF COPPER AND ALUMINUM". Physical and Chemical Aspects of the Study of Clusters, Nanostructures and Nanomaterials, nr 12() (15.12.2020): 120–27. http://dx.doi.org/10.26456/pcascnn/2020.12.120.
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В настоящей работе предпринимается попытка выявить особенности структуры контактных прослоек при контактном плавлении меди с алюминием марки АМГ-2 (состав мас. %: Mg - 1,8-2,8, Mn - 0,2-0,6, Cu - 0,1, Zn - 0,2, Fe - 0,4, Si - 0,4, остальное - алюминий) и алюминий-литиевым сплавом ( Al - 0,4 ат. % Li ). Изучение контактного плавления в системе Cu / Al важно для разработки технологии контактно-реактивной пайки, получения слоистых интерметаллических композиционных материалов, создания теплоотводов полупроводниковых приборов, моделирование дендритообразования. Установлено, что в контактных прослойках образуются интерметаллиды, влияющие на хрупкость соединений меди с алюминием и эвтектические структуры. In this work, an attempt is made to identify the features of the structure of contact layers during the contact melting of copper with aluminum brand AMG-2 (mass composition, %: Mg - 1,8 - 2,8, Mn - 0,2 - 0,6, Cu - 0,1, Zn - 0,2, Fe - 0,4, Si - 0,4, rest - aluminum) and aluminum-lithium alloy (Al - 0,4 wt.% Li). The study of contact melting in the system is important for development of contact-reactive soldering technology, obtaining layered intermetallic composite materials, creating heat sinks for semiconductor devices, modeling dendrite formation. It was established that intermetallic compounds are formed in the contact layers, which affect the brittleness of copper-aluminum compounds and eutectic structures.
Rozprawy doktorskie na temat "Intermetallic-Intermetallic eutectic composite alloy"
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Sees, Jennifer A. (Jennifer Anne). "Solid State Diffusion Kinetics of Intermetallic Compound Formation in Composite Solder". Thesis, University of North Texas, 1993. https://digital.library.unt.edu/ark:/67531/metadc279330/.
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The Sn/Pb eutectic alloy system is the most widely used joining material in the electronics industry. In this application, the solder acts as both an electrical and mechanical connection within and among the different packaging levels in an electronic device. Recent advances in packaging technologies, however, driven by the desire for miniaturization and increased circuit speed, result in severe operating conditions for the solder connection. In an effort to improve its mechanical integrity, metallic or intermetallic particles have been added to eutectic Sn/Pb solder, and termed composite solders. It was the goal of this study to investigate the growth and morphology of the two intermetallic phases (Cu6Sn5 and Cu3Sn) that form between a Cu substrate and Sn/Pb solder under different aging and annealing conditions.
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SONG, HYO-JIN. "PROCESSING PHASE TRANS". University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1132249697.
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Ayturk, Mahmut Engin. "Synthesis, annealing strategies and in-situ characterization of thermally stable composite thin Pd/Ag alloy membranes for hydrogen separation". Worcester, Mass. : Worcester Polytechnic Institute, 2007. http://www.wpi.edu/Pubs/ETD/Available/etd-042307-012951/.
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Thesis (Ph.D.)--Worcester Polytechnic Institute.Keywords: composite Pd and Pd/Ag membranes, alloying, Pd/Ag barrier, intermetallic diffusion, bi-metal multi-layer BMML deposition, electroless plating kinetics, high temperature x-ray diffraction, aluminum hydroxide surface grading, porous sintered metal supports, hydrogen separation. Includes bibliographical references (leaves 279-296 ).
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El, Aoud Bouthaina. "Etude et optimisation de l'usinage par faisceau laser des alliages de titane et des matériaux composites intermétalliques à base de titane". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLC048.
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La technologie laser est couramment utilisée dans les industries aéronautiques depuis les années 1980. La découpe au laser, comme étant un procédé d’enlèvement de matière, offre plus d’avantages que les procédés conventionnels de la découpe. Parmi les apports du laser, l’absence de contact mécanique avec le matériau à usiner, une limitation de contamination des matériaux et une production élevée due à une haute vitesse de coupe. Les alliages de titane et les composites intermétalliques à base de titane jouent un rôle important dans le domaine de la science et de l’ingénierie ainsi ils permettent de satisfaire les activités de fabrication avancée dans les industries aéronautiques. L’amélioration de ce procédé de fabrication est souhaitable pour augmenter les performances techniques et accentuer l’intérêt économique. Les travaux réalisés ont porté sur l’étude et l’analyse des effets des paramètres de l’usinage par faisceau laser sur l’intégrité de la surface en termes de qualité et morphologie de la surface usinée de plusieurs matériaux, tels que, le titane pur, les alliages de titaneTi-6Al-4V et Ti6242 et le composite intermétallique à base de titane afin d’optimiser les conditions de découpage par laser.La sélection des paramètres de coupe dans le processus d’usinage laser tels que la puissance du laser, la vitesse de coupe, la pression du gaz d’assistance est importante pour assurer l’exactitude de l’usinage et l’amélioration de la microstructure, la rugosité, la zone affectée thermiquement, la largeur de la saignée, la micro dureté et le taux d’enlèvement de matière, résultant des sollicitations mécaniques et thermiques subies durant les différentes étapes de production.Cette étude se base sur une approche empirique faisant intervenir la méthodologie des plans d’expériences (ANOVA, Taguchi), la technique de la logique floue et les méthodes de décision multicritères (FTOPSIS, GRA) pour définir d’une façon rationnelle les essais expérimentaux visant à optimiser les conditions de découpe au laser dans le but de maximiser la production en assurant une meilleure qualité de fabricationLaser technology has been widely used in the aeronautics industry since the 1980s. Laser cutting, as a material removal process, offers more advantages than conventional cutting processes. Among the contributions of the laser, the absence of mechanical contact with the material, a limitation of contamination of the materials and a high production due to a high cutting speed. Titanium alloys and titanium-based intermetallic composites have an important role in the field of science and engineering, making it possible to satisfy advanced manufacturing activities in the aerospace industries. Improvement of this manufacturing process is desirable to increase technical performance and economic interest. The present framework focused on study and analysis of the effects of laser beam machining parameters on the surface integrity in terms of quality and morphology of several materials, such as pure titanium, titanium alloysTi-6Al-4V and Ti6242 and the titanium-based intermetallic composite to optimize laser cutting conditions.Selection of cutting parameters in the laser machining process such as laser power, cutting speed, assist gas pressure is important to ensure machining accuracy and microstructure , roughness, heat affected zone, kerf width, microhardness and rate of removal of material improvement, resulting from the mechanical and thermal stresses undergone during the different stages of production.This study is based on an empirical approach involving the experimental design methodology (ANOVA, Taguchi), the fuzzy logic technique and the multicriteria decision methods (FTOPSIS, GRA) aiming at optimizing laser cutting conditions in order to maximize production by ensuring better manufacturing quality
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Wolski, Krzysztof. "Influence de la dispersion de phases céramiques sur la résistance au fluage de l'intermétallique FeAl". Grenoble INPG, 1994. http://www.theses.fr/1994INPG4207.
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L'objectif du present travail etait d'ameliorer la resistance au fluage de l'intermetallique feal par dispersion d'une phase ceramique. Les materiaux ont ete prepares par mecanosynthese ou par attrition, toutes deux couplees a l'oxydation in situ et suivies du frittage sous charge. Les phenomenes physico-chimiques, intervenant au cours de l'elaboration, ont ete analyses: la formation complete de feal par mecanosynthese a ete demontree (atd, drx, mossbauer), l'utilisation du lubrifiant (acide stearique) conduit a la formation du carbure fragilisant fe#3alc#0#,#7, ce carbure a ete transforme en zrc par l'ajout de zrh#2 ou elimine par suppression du lubrifiant, la dispersion formee par oxydation in situ est plus efficace que l'ajout de poudres ceramiques, les produits d'oxydation sont transformes au cours du frittage (t#f<1150c) en spinelle feal#2o#4, l'augmentation de t#f conduit a la transformation du spinelle en -al#2o#3, qui coalesce par la suite. L'optimisation des cycles de broyage et de frittage (oxydation in situ, suppression du lubrifiant et diminution de t#f) a permis d'elaborer des composites feal-feal#2o#4, ou le spinelle (5 a 15 vol%) est present sous forme d'une dispersion nanometrique (10 a 50 nm). Les proprietes rheologiques des composites feal-feal#2o#4, ont ete analysees par des essais de compression a vitesse de deformation imposee (3. 10#-#6 - 3. 10#-#4s#-#1) a 727c, et decrites a l'aide d'une loi puissance sans contrainte seuil d/dt=a#n. La contrainte d'ecoulement (=350 mpa) et le coefficient de sensibilite a la contrainte (n=13) sont triples par rapport au feal non renforce (=105 mpa, n=4), ce qui procure a ces composites un excellent comportement au fluage. Cette amelioration est essentiellement due a la dispersion nanometrique du spinelle, dont la stabilite a ete analysee du point de vue de la cinetique de coalescence et verifiee experimentalement
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Sharma, Abhishek. "An Evaluation of the Mechanical Behavior of some new High Temperature Materials". Thesis, 2018. https://etd.iisc.ac.in/handle/2005/5254.
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Two new high-temperature alloy systems have been discovered recently at the Indian
Institute of Science, which form the basis of this thesis. The first alloy system is an
Intermetallic-Intermetallic eutectic composite alloy in the nickel-rich end of the Ni-Al-
Zr ternary system, first reported by Tiwary et al. These eutectic composites have very
impressive room temperature yield strengths of about 2 GPa which are retained till
about 700 . Coupled with 2 to 5% tensile plasticity at room temperature, excellent
high-temperature oxidation resistance, good long-term microstructural stability and very
low densities of about 7.35–7.95 gm/cm3, these materials are exciting candidates for
high-temperature applications.
The second alloy system comprises of Tungsten free Cobalt based superalloys having
the classical
−
0 microstructure similar to that of nickel-based superalloys as described
by Makineni et al. The presence of the L12 phase in cobalt-based systems was reported
by Lee et al. and Sato et al. where the addition of 25 wt.% tungsten seemed to stabilize
the metastable Co3Al. This however pushed the density of the alloy to about 9–10
gm/cm3, making it too heavy for most high-temperature applications. A large body of
work followed trying to reduce or eliminate the presence of tungsten in these alloys. The
new alloys by Makineni et al. do not contain tungsten which reduces the density to about
8.0–8.4 gm/cm3.
The high-temperature mechanical behavior of some of the alloys from these two sysi
tems has been evaluated in the current thesis. This thesis is divided into six chapters.
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Tiwary, Chandra Sekhar. "Microstructural, Mechanical and Oxidation Behavior of Ni-Al-Zr Ternary Alloys". Thesis, 2014. https://etd.iisc.ac.in/handle/2005/2991.
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The thesis introduces a novel alloy system based on submicron distributions of intermetallic phases realised through eutectic solidification in the ternary system Ni-Al-Zr. Various compositions in this system comprising of intermetallic phases distributed in different eutectic structures show ultra-high strength at temperatures upto 700°C combined with reasonable tensile plasticity, exceptional oxidation resistance and high temperature structural stability. Intermetallics have long been used in high temperature alloys systems such as in the classical Ni-base superalloys that derive their strength from nanoscale dispersions of the aluminide, Ni3Al(γ’) in a matrix of disordered fcc Ni (γ), alloyed with expensive, high density refractory elements such as Re and Ru. The high temperature applications of intermetallics derive from their strength retention to high temperatures, creep resistance enabled by low diffusion rates, and attractive oxidation resistance based on high concentration of elements such as Al that forms stable oxides. Several decades of effort on the development of new generation of intermetallic alloys through the 80’s and 90’s have gone unrewarded, with the exception of TiAl based alloys that are now used in recent generation aircraft engines. The promise of intermetallics as high temperature candidate materials is limited by their poor ductility or toughness arising from several intrinsic properties such as low grain boundary cohesive strength (in the case of Ni3Al) or an insufficient number of slip systems (as in NiAl) or extrinsic effects such as embrittlement by hydrogen (Fe3Al) that derive fundamentally from the existence of directionality in bonding.
However, low ductility or toughness can often be alleviated by limiting the length scale for slip. We have therefore examined the possibility of combining intermetallics in the form of eutectic structures, potentially limiting slip lengths within each intermetallic constituent. Eutectic structures in binary systems limit the choice of intermetallic combinations so that finding such combinations with engineering potential is difficult. On the other hand combinations of three elements or more would enable a significantly larger set of permutations of eutectic intermetallics, provided the constituent binary phase diagrams contain either eutectic or peritectic reactions involving intermetallic phases, as well as intermediate intermetallic phases.
The ternary Ni-Al-Zr system met our criterion in several ways. The Ni-Al binary phase diagram shows a peritectic reaction from liquid and NiAl (Pm 3m, B2 with a lattice parameter of 0.288nm) to form Ni3Al (Pm 3m, L12 with a lattice parameter of 0.356 nm), intermetallics that have been extensively investigated in earlier literature. The Ni-Zr system shows a peritectic reaction between liquid and the Ni7Zr2 (C12/m1 with a lattice parameters a=0.469nm, b=0.823nm, c=1.219nm) phase to form the intermetallic Ni5Zr
(F 43m with a lattice parameter of 0.670nm). Further the NiAl and Ni7Zr2 are both intermediate phases and should therefore form a mono-variant eutectic on the composition line joining these two phases in the ternary system. We note that Zr participates in many glass forming systems. In the Ni-Zr system, for example, glass forming ability has been associated with the structure of the liquid phase and associated low diffusivity. As a consequence, a fine scale eutectic structure may be expected. Zr has also been reported to strengthen and ductilise Ni3Al and NiAl. Finally, both Al and Zr form stable oxides and might promote oxidation resistance.
After introducing the thesis in Chapter 1, the experimental details are outlined in the Chapter 2. The experimental results and subsequent discussions are presented in three subsequent chapters. Chapter 3 reports the microstructural aspects of as cast alloys in this ternary system Previous literature and our analysis of phase equilibria in the Ni-Al-Zr system based on Thermo-Calc, suggested that solidification from the liquid to form the Ni3Al + Ni5Zr, Ni3Al + Ni7Zr2 and NiAl+ Ni7Zr2 eutectics is possible. We obtained eutectic structures involving combinations of these intermetallic phases along a constant zirconium section at 11 at. %. The alloy A (Ni-77 at.%, Zr-11at.% and rest Al) contains eutectic structures containing the Ni3Al and Ni5Zr phases in two morphologies, a planar, lamellar structure and a more irregular form. The alloys B (Ni-74 at.%, Zr-11at.% and rest Al) and C (Ni-71 at.%, Zr-11at.% and rest Al) contain two different eutectic structures that combine the Ni3Al and Ni7Zr2 phases, and the NiAl and Ni7Zr2 phases. These phases were identified by a combination of X-ray diffraction, transmission electron microscopy coupled with energy dispersive spectroscopy and electron probe microanalysis. The volume fraction of each eutectic constituent is different in the two compositions in that alloy B(Ni-74 at.%, Zr-11at.% and rest Al) contains significantly higher volume fractions of the eutectic containing the Ni3Al and Ni7Zr2 phases than the alloy C (Ni-71 at.%, Zr¬11at.% and rest Al). In order to understand effect of individual phases we have melted several other alloys (alloy D to I) bounding these eutectic alloys (7-25 at.% Al, 5-15 at.% Zr and rest Ni) that form primary solidification phases of the intermetallic structures that constitute the eutectics.
Chapter 4 discusses the mechanical behaviour of the fully eutectic alloys alloys as well as alloys with a combination of primary phases along with a eutectic. Mechanical behaviour was assessed in vacuum arc melted and suction cast material. The compressive strength of eutectic and off-eutectic compositions has been evaluated as a function of temperature. Very high strength levels of around 2 GPa could be achieved accompanied by reasonable room temperature tensile plasticity in the range 3-4%. The introduction of the respective primary phases of NiAl, Ni3Al, Ni5Zr and Ni7Zr2 results in decrease of strength. We have explored the origins of strength and tensile plasticity in alloys through micro and pico indentation (hardness) measurements and an examination of slip lines and crack initiation on pre-polished surface of the tensile tested samples as well as by transmission electron microscopy. Chapter 5 explores the oxidation resistance of these alloys in isothermal tests. The oxidation resistance of alloys compares well with recently developed cast single crystal alloys. Clearly, the oxide scale is extremely adherent and no spalling occurs. Electron microprobe analysis shows the presence of a fine scale, layered oxide structures and reaction zones within the substrate. The oxidation behaviour has been characterized using TGA, XRD and EPMA. We have attempted to understand the mechanism of oxidation through analysis of rate constants and activation energy coupled with microstructural observations. Chapter 6 presents a summary of the current work and present the scope for further work.
8
Tiwary, Chandra Sekhar. "Microstructural, Mechanical and Oxidation Behavior of Ni-Al-Zr Ternary Alloys". Thesis, 2014. http://etd.iisc.ernet.in/handle/2005/2991.
Pełny tekst źródłaStreszczenie:
The thesis introduces a novel alloy system based on submicron distributions of intermetallic phases realised through eutectic solidification in the ternary system Ni-Al-Zr. Various compositions in this system comprising of intermetallic phases distributed in different eutectic structures show ultra-high strength at temperatures upto 700°C combined with reasonable tensile plasticity, exceptional oxidation resistance and high temperature structural stability. Intermetallics have long been used in high temperature alloys systems such as in the classical Ni-base superalloys that derive their strength from nanoscale dispersions of the aluminide, Ni3Al(γ’) in a matrix of disordered fcc Ni (γ), alloyed with expensive, high density refractory elements such as Re and Ru. The high temperature applications of intermetallics derive from their strength retention to high temperatures, creep resistance enabled by low diffusion rates, and attractive oxidation resistance based on high concentration of elements such as Al that forms stable oxides. Several decades of effort on the development of new generation of intermetallic alloys through the 80’s and 90’s have gone unrewarded, with the exception of TiAl based alloys that are now used in recent generation aircraft engines. The promise of intermetallics as high temperature candidate materials is limited by their poor ductility or toughness arising from several intrinsic properties such as low grain boundary cohesive strength (in the case of Ni3Al) or an insufficient number of slip systems (as in NiAl) or extrinsic effects such as embrittlement by hydrogen (Fe3Al) that derive fundamentally from the existence of directionality in bonding.
However, low ductility or toughness can often be alleviated by limiting the length scale for slip. We have therefore examined the possibility of combining intermetallics in the form of eutectic structures, potentially limiting slip lengths within each intermetallic constituent. Eutectic structures in binary systems limit the choice of intermetallic combinations so that finding such combinations with engineering potential is difficult. On the other hand combinations of three elements or more would enable a significantly larger set of permutations of eutectic intermetallics, provided the constituent binary phase diagrams contain either eutectic or peritectic reactions involving intermetallic phases, as well as intermediate intermetallic phases.
The ternary Ni-Al-Zr system met our criterion in several ways. The Ni-Al binary phase diagram shows a peritectic reaction from liquid and NiAl (Pm 3m, B2 with a lattice parameter of 0.288nm) to form Ni3Al (Pm 3m, L12 with a lattice parameter of 0.356 nm), intermetallics that have been extensively investigated in earlier literature. The Ni-Zr system shows a peritectic reaction between liquid and the Ni7Zr2 (C12/m1 with a lattice parameters a=0.469nm, b=0.823nm, c=1.219nm) phase to form the intermetallic Ni5Zr
(F 43m with a lattice parameter of 0.670nm). Further the NiAl and Ni7Zr2 are both intermediate phases and should therefore form a mono-variant eutectic on the composition line joining these two phases in the ternary system. We note that Zr participates in many glass forming systems. In the Ni-Zr system, for example, glass forming ability has been associated with the structure of the liquid phase and associated low diffusivity. As a consequence, a fine scale eutectic structure may be expected. Zr has also been reported to strengthen and ductilise Ni3Al and NiAl. Finally, both Al and Zr form stable oxides and might promote oxidation resistance.
After introducing the thesis in Chapter 1, the experimental details are outlined in the Chapter 2. The experimental results and subsequent discussions are presented in three subsequent chapters. Chapter 3 reports the microstructural aspects of as cast alloys in this ternary system Previous literature and our analysis of phase equilibria in the Ni-Al-Zr system based on Thermo-Calc, suggested that solidification from the liquid to form the Ni3Al + Ni5Zr, Ni3Al + Ni7Zr2 and NiAl+ Ni7Zr2 eutectics is possible. We obtained eutectic structures involving combinations of these intermetallic phases along a constant zirconium section at 11 at. %. The alloy A (Ni-77 at.%, Zr-11at.% and rest Al) contains eutectic structures containing the Ni3Al and Ni5Zr phases in two morphologies, a planar, lamellar structure and a more irregular form. The alloys B (Ni-74 at.%, Zr-11at.% and rest Al) and C (Ni-71 at.%, Zr-11at.% and rest Al) contain two different eutectic structures that combine the Ni3Al and Ni7Zr2 phases, and the NiAl and Ni7Zr2 phases. These phases were identified by a combination of X-ray diffraction, transmission electron microscopy coupled with energy dispersive spectroscopy and electron probe microanalysis. The volume fraction of each eutectic constituent is different in the two compositions in that alloy B(Ni-74 at.%, Zr-11at.% and rest Al) contains significantly higher volume fractions of the eutectic containing the Ni3Al and Ni7Zr2 phases than the alloy C (Ni-71 at.%, Zr¬11at.% and rest Al). In order to understand effect of individual phases we have melted several other alloys (alloy D to I) bounding these eutectic alloys (7-25 at.% Al, 5-15 at.% Zr and rest Ni) that form primary solidification phases of the intermetallic structures that constitute the eutectics.
Chapter 4 discusses the mechanical behaviour of the fully eutectic alloys alloys as well as alloys with a combination of primary phases along with a eutectic. Mechanical behaviour was assessed in vacuum arc melted and suction cast material. The compressive strength of eutectic and off-eutectic compositions has been evaluated as a function of temperature. Very high strength levels of around 2 GPa could be achieved accompanied by reasonable room temperature tensile plasticity in the range 3-4%. The introduction of the respective primary phases of NiAl, Ni3Al, Ni5Zr and Ni7Zr2 results in decrease of strength. We have explored the origins of strength and tensile plasticity in alloys through micro and pico indentation (hardness) measurements and an examination of slip lines and crack initiation on pre-polished surface of the tensile tested samples as well as by transmission electron microscopy. Chapter 5 explores the oxidation resistance of these alloys in isothermal tests. The oxidation resistance of alloys compares well with recently developed cast single crystal alloys. Clearly, the oxide scale is extremely adherent and no spalling occurs. Electron microprobe analysis shows the presence of a fine scale, layered oxide structures and reaction zones within the substrate. The oxidation behaviour has been characterized using TGA, XRD and EPMA. We have attempted to understand the mechanism of oxidation through analysis of rate constants and activation energy coupled with microstructural observations. Chapter 6 presents a summary of the current work and present the scope for further work.
9
Gunjal, Vilas Vishnu. "Microstructural, Mechanical and Oxidation Behavior of Ni-Al-Zr Intermetallic Eutectic Alloys". Thesis, 2016. http://etd.iisc.ac.in/handle/2005/2965.
Pełny tekst źródłaStreszczenie:
The excellent high temperature microstructure stability, high strength, and oxidation resistance of intermetallics has for long driven the development of intermetallic based alloys. More recent studies demonstrated attractive properties of eutectic intermetallic in the Ni-Al-Zr systems. This thesis deals with study of binary Ni3Al+Ni7Zr2, NiAl+Ni7Zr2 and Ni3Al+NiAl+Ni7Zr2 ternary intermetallic eutectic alloys in this system and includes the identification of compositions that would yield each eutectic structure and their microstructural characterization, mechanical and oxidation behavior. The thesis is divided into six chapters. Chapter 1 reviews the study on high temperature materials development and presents the objectives of work in the current thesis. Various experimental techniques used for alloy preparation (vacuum arc melting and vacuum suction casting), microstructural characterization (optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray Diffraction (XRD), electron probe micro analyzer (EPMA), differential scanning calorimetry (DSC)), compression tests, microhardness tests and thermo gravimetric analysis (TGA) are described in Chapter 2. The specific background of work related to each chapter together with experimental results and discussion are given in next three chapters. Chapter 3 reports the method of identification of the composition for each of the eutectic alloys referred to above. The identification of alloy compositions of binary eutectics Ni3Al+Ni7Zr2 (Ni-13.5Al-11Zr), NiAl+Ni7Zr2 (Ni-19Al-12Zr) and Ni3Al+NiAl+Ni7Zr2 ternary eutectic (Ni-18.4Al-11.6Zr) is carried out with the help of available liquidus projection of Ni-Al-Zr system, and the iterative melting of numerous compositions that were refined to define the critical compositions for each eutectic. The microstructural features of these alloys have been characterized using optical and electron microscopy. Phase identification is confirmed by X ray diffraction, EPMA and TEM. The microstructure of Ni3Al+Ni7Zr2 and Ni3Al+NiAl+Ni7Zr2 ternary eutectic alloy shows similar eutectic morphologies. The eutectic colony consists of lamellar plates at center and intermixed lamellar-rod irregular morphologies towards the boundaries of the colonies. However, the NiAl+Ni7Zr2 eutectic alloy shows a fine, lamellar plate morphology throughout the microstructure. The orientation relationship between eutectic phases is determined using TEM technique for each alloy composition. Onsets of melting and liquidus temperatures have been identified by Differential Scanning Calorimetry. Modified liquidus projections of Ni-Al-Zr system near the Ni3Al+NiAl+Ni7Zr2 ternary eutectic region have been derived from present experimental work. Chapter 4 focuses on understanding the mechanical behaviour of these individual eutectics at room temperature and high temperature. An attempt has been made to correlate the microstructure and mechanical properties of eutectics by measuring room temperature hardness, compressive yield strength at various temperatures, and examination of slip bands, crack initiation and fractography. It is observed that NiAl+Ni7Zr2 eutectic possesses the highest yield strength and hardness followed by ternary eutectic and then the Ni3Al+Ni7Zr2 eutectic. The yield strength of these eutectics decreases rapidly beyond 700oC and this decrease is accompanied by substantial increase in compressive ductility and steady state flow, with little work hardening. Chapter 5 explores the isothermal oxidation behavior at high temperatures of these eutectic alloys. Oxidation kinetics have been measured at various temperatures (900oC, 1000oC, 1050oC and 1100oC) are carried out using the thermo gravimetric analysis technique (TGA). The oxidation behavior has been characterized using TGA, X ray diffraction and EPMA. The Top surface of oxide layer shows compact, NiO layer with a fine grain size. The cross section of oxide samples shows five distinct microstructural and compositional layers at steady state. Attempt has been made to understand the oxidation mechanism, sequence of layer formation in correlation with microstructure and weight gains, rate constants and activation energy analysis. Finally Chapter 6 presents a summary of the current work and suggests for further work.
10
Gunjal, Vilas Vishnu. "Microstructural, Mechanical and Oxidation Behavior of Ni-Al-Zr Intermetallic Eutectic Alloys". Thesis, 2016. http://etd.iisc.ernet.in/handle/2005/2965.
Pełny tekst źródłaStreszczenie:
The excellent high temperature microstructure stability, high strength, and oxidation resistance of intermetallics has for long driven the development of intermetallic based alloys. More recent studies demonstrated attractive properties of eutectic intermetallic in the Ni-Al-Zr systems. This thesis deals with study of binary Ni3Al+Ni7Zr2, NiAl+Ni7Zr2 and Ni3Al+NiAl+Ni7Zr2 ternary intermetallic eutectic alloys in this system and includes the identification of compositions that would yield each eutectic structure and their microstructural characterization, mechanical and oxidation behavior. The thesis is divided into six chapters. Chapter 1 reviews the study on high temperature materials development and presents the objectives of work in the current thesis. Various experimental techniques used for alloy preparation (vacuum arc melting and vacuum suction casting), microstructural characterization (optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray Diffraction (XRD), electron probe micro analyzer (EPMA), differential scanning calorimetry (DSC)), compression tests, microhardness tests and thermo gravimetric analysis (TGA) are described in Chapter 2. The specific background of work related to each chapter together with experimental results and discussion are given in next three chapters. Chapter 3 reports the method of identification of the composition for each of the eutectic alloys referred to above. The identification of alloy compositions of binary eutectics Ni3Al+Ni7Zr2 (Ni-13.5Al-11Zr), NiAl+Ni7Zr2 (Ni-19Al-12Zr) and Ni3Al+NiAl+Ni7Zr2 ternary eutectic (Ni-18.4Al-11.6Zr) is carried out with the help of available liquidus projection of Ni-Al-Zr system, and the iterative melting of numerous compositions that were refined to define the critical compositions for each eutectic. The microstructural features of these alloys have been characterized using optical and electron microscopy. Phase identification is confirmed by X ray diffraction, EPMA and TEM. The microstructure of Ni3Al+Ni7Zr2 and Ni3Al+NiAl+Ni7Zr2 ternary eutectic alloy shows similar eutectic morphologies. The eutectic colony consists of lamellar plates at center and intermixed lamellar-rod irregular morphologies towards the boundaries of the colonies. However, the NiAl+Ni7Zr2 eutectic alloy shows a fine, lamellar plate morphology throughout the microstructure. The orientation relationship between eutectic phases is determined using TEM technique for each alloy composition. Onsets of melting and liquidus temperatures have been identified by Differential Scanning Calorimetry. Modified liquidus projections of Ni-Al-Zr system near the Ni3Al+NiAl+Ni7Zr2 ternary eutectic region have been derived from present experimental work. Chapter 4 focuses on understanding the mechanical behaviour of these individual eutectics at room temperature and high temperature. An attempt has been made to correlate the microstructure and mechanical properties of eutectics by measuring room temperature hardness, compressive yield strength at various temperatures, and examination of slip bands, crack initiation and fractography. It is observed that NiAl+Ni7Zr2 eutectic possesses the highest yield strength and hardness followed by ternary eutectic and then the Ni3Al+Ni7Zr2 eutectic. The yield strength of these eutectics decreases rapidly beyond 700oC and this decrease is accompanied by substantial increase in compressive ductility and steady state flow, with little work hardening. Chapter 5 explores the isothermal oxidation behavior at high temperatures of these eutectic alloys. Oxidation kinetics have been measured at various temperatures (900oC, 1000oC, 1050oC and 1100oC) are carried out using the thermo gravimetric analysis technique (TGA). The oxidation behavior has been characterized using TGA, X ray diffraction and EPMA. The Top surface of oxide layer shows compact, NiO layer with a fine grain size. The cross section of oxide samples shows five distinct microstructural and compositional layers at steady state. Attempt has been made to understand the oxidation mechanism, sequence of layer formation in correlation with microstructure and weight gains, rate constants and activation energy analysis. Finally Chapter 6 presents a summary of the current work and suggests for further work.
Książki na temat "Intermetallic-Intermetallic eutectic composite alloy"
1
Mitra, Rahul. Structural Intermetallics and Intermetallic Matrix Composites. Taylor & Francis Group, 2015.
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2
Structural Intermetallics and Intermetallic Matrix Composites. Taylor & Francis Group, 2015.
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3
Mitra, Rahul. Structural Intermetallics and Intermetallic Matrix Composites. Taylor & Francis Group, 2015.
Znajdź pełny tekst źródłaCzęści książek na temat "Intermetallic-Intermetallic eutectic composite alloy"
1
Gatamorta, F., Dhurata Katundi, E. Bayraktar, L. M. P. Ferreira i M. L. N. M. Melo. "Magnetic Shape Memory Composite (MSMC) Design from Intermetallic Cu-NiTi-MnAl-Fe3O4 Alloy as an Alternative Replacement for Actuators". W Mechanics of Composite and Multi-functional Materials, Volume 5, 47–53. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-30028-9_7.
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2
Wierzchon, T., i M. Ossowski. "Structure and Properties of α+β Titanium Alloy - TixAly Intermetallic Phases Laminate Composite". W Advances in Science and Technology, 1287–92. Stafa: Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/3-908158-01-x.1287.
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3
Warmuzek, Malgorzata. "Polyphase Eutectics of Aluminum Alloys: Effect of Phase Composition". W Encyclopedia of Aluminum and Its Alloys. Boca Raton: CRC Press, 2019. http://dx.doi.org/10.1201/9781351045636-140000255.
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The polyphase eutectics (α-Al+intermetallic+Si) constituting the final aluminum alloy microstructure were characterized by their phase composition, growth mechanism, and morphology of eutectic crystals. The main groups of eutectic phase constituents were presented with a special attention paid to intermetallic phases. Morphology of different types of polyphase eutectics, among those divorced, was characterized and presented (as microscopic images) on microphotographs. The microstructural effects of stable and metastable phases competition in the stage of nucleation and growth of polyphase eutectics as affected by local cooling rate and liquid alloy composition were described. Some examples of the evolution of the phase composition of eutectics in commercial alloys due to modifications of technological procedures were presented.
4
"The Effects of Microstructure on Properties". W Aluminum Alloy Castings, 39–46. ASM International, 2004. http://dx.doi.org/10.31399/asm.tb.aacppa.t51140039.
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Abstract In castings, microstructural features are products of metal chemistry and solidification conditions. The microstructural features, excluding defects, that most strongly affect the mechanical properties or aluminum castings are size, form, and distribution of intermetallic phases; dendrite arm spacing; grain size and shape; and eutectic modification and primary phase refinement. This chapter discusses the effects of these microstructural features on properties and methods for controlling them. The chapter concludes with a detailed examination of the refinement of hypereutectic aluminum-silicon alloys.
5
Manilevich, F., Yu Pirskyy, A. Kutsyi, V. Berezovets i V. Yartys. "Activated aluminum for hydrogen generation from water". W HYDROGEN BASED ENERGY STORAGE: STATUS AND RECENT DEVELOPMENTS, 81–93. Institute for Problems in Materials Science, 2021. http://dx.doi.org/10.15407/materials2021.081.
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Al-based alloys and mechanochemically activated aluminum powders were prepared in this study, and the regularities of their hydrolysis reaction with water were studied. Aluminum alloys were prepared by melting aluminum with additions of Ga–In–Sn eutectic (5 wt.%), bismuth (3 wt.%), antimony (3 wt.%), or zinc (3 wt.%). The temperature-dependent kinetics of their hydrolysis in a temperature range 25–70 °C was studied by using a volumetric technique. The most efficient activation of the hydrolysis process was achieved for the Al–Ga– In–Sn-Zn alloy, particularly at low temperatures (5 and 25° C). The addition of bismuth to the Al–Ga–In–Sn alloy significantly decreases the hydrolysis rate, whereas the addition of antimony has only a weak effect on the process, despite the fact that the standard electrode potentials of bismuth and antimony have rather close values. Commercially available aluminum PA-4 and ASD-1 powders were mechanochemically activated by Ga–In–Sn or Ga–In–Sn–Zn eutectic alloys (5 wt.%) and graphite (1–3 wt.%) in a mixer type ball mill. Subsequently, they were pressed (P = 4 MPa) into the pellets, which were used to generate hydrogen from water via the hydrolysis process. X-ray diffraction study of the milled PA-4 powder revealed the presence of four phases, including aluminum, graphite, and two In–Sn intermetallic compounds (In3Sn and In1–xSnx, were x ≈ 0.04). The quantitative analysis by EDX showed a uniform distribution of the activating additives over the pellet surface, while the graphite was partly aggregated. Studies on the hydrolysis kinetics when utilizing Al-based pellets demonstrated that the process readily proceeds at temperatures ≥ 5° C. At the same time, the efficiency of hydrogen generation depends on the amount of the added graphite, particle size of aluminum powders, duration and medium of their mechanochemical treatment, and the hydrolysis temperature.
6
Prakash, Chander, Sunpreet Singh, Ahmad Majdi Abdul-Rani, M. S. Uddin, B. S. Pabla i Sanjeev Puri. "Spark Plasma Sintering of Mg-Zn-Mn-Si-HA Alloy for Bone Fixation Devices". W Handbook of Research on Green Engineering Techniques for Modern Manufacturing, 282–95. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-5445-5.ch015.
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In this chapter, low elastic modulus porous Mg-Zn-Mn-(Si, HA) alloy was fabricated by mechanical alloying and spark plasma sintering technique. The microstructure, topography, elemental, and chemical composition of the as-sintered bio-composite were characterized by optical microscope, FE-SEM, EDS, and XRD technique. The mechanical properties such as hardness and elastic modulus were determined by nanoindentation technique. The as-sintered bio-composites show low ductility due to the presence of Si, Ca, and Zn elements. The presence of Mg matrix was observed as primary grain and the presence of coarse Mg2Si, Zn, and CaMg as a secondary grain boundary. EDS spectrum and XRD pattern confirms the formation of intermetallic biocompatible phases in the sintered compact, which is beneficial to form apatite and improved the bioactivity of the alloy for osseointegration. The lowest elastic modulus of 28 GPa was measured. Moreover, the as-sintered bio-composites has high corrosion resistance and corrosion rate of the Mg was decreased by the addition of HA and Si element.
Streszczenia konferencji na temat "Intermetallic-Intermetallic eutectic composite alloy"
1
Li, Y. L., C. L. Ma i H. Zhang. "Crystallographic Orientation Evolution in NbSS-Nb5Si3 Eutectic Alloys by EBSD Analyses". W ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-95309.
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The progresses in high temperature materials encourage the development of turbine engine in terms of thrust and efficiency. Ni-based superalloys, which are predominant in elevated temperature application, have limited potential to raise serving temperature. In-situ composites, such as Cr-Cr3Si, NiAl-Cr and Nb-Nb5Si3 eutectic alloys, consisting of a ductile metallic phase and a hard intermetallic phase, are attractive candidates to replace Ni-based superalloys. The microstructure and mechanical properties of these in-situ composites are widely investigated. However, little work is focused on crystallography of in-situ composites, except for preferred growth direction and crystallographic orientation relationship. In this paper, Nb-Si-Mo-based alloys were fabricated by non-consumable arc melting, and then were directionally solidified in an optical floating zone (OFZ) melting furnace. The crystallographic orientation evolutions in Nb-Nb5Si3 eutectic alloy are studied by electron back-scattered diffraction (EBSD) analyses. First, the effect of solidification condition on crystallographic orientation is examined. The as-cast alloy displays cellular microstructure. The Nb phase shows different crystallographic orientations in different cells, while the Nb5Si3 phase shows similar crystallographic orientation in a number of cells. In directionally solidified alloys, when growth rate is 5mm/h without seed rod rotation, the grain sizes of Nb and Nb5Si3 are both several millimeter. As growth rate rises or seed rod rotates, the grain size of Nb decreases much more drastically than that of Nb5Si3. Thus, solidification condition is supposed to influence nucleation of the Nb phase rather than the Nb5Si3 phase. Second, the effect of annealing on crystallographic orientation is studied. The Nb5Si3 has three allotropic phases. The allotropic phase transformations occur through annealing, during which the Nb5Si3 grain size decreases.
2
Lin, D. C., C. Y. Kuo, T. S. Srivatsan i G. X. Wang. "Understanding Solidification Kinetics and Microstructural Development of a Lead-Free Composite Solder". W ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-42544.
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This paper presents and discusses the solidification of Sn-Ag eutectic solder and the effect of cooling rate on its microstructure formation with and without addition of nanosized copper powders. The composite solder mixture was mechanically mixed, and subsequently melted in an aluminum crucible placed in a temperature-controlled furnance, prior to promoting solidification. For all cases significant undercooling of the melt was observed prior to solidification. A reduction in the solidification temperature occurred by the addition of copper nanopowders. Optical microscopy observations revealed the microstructure of solders, in the as-solidified condition, to be appreciably altered by the addition of nanosized copper powders. The copper nanopowders were precipitated as an intermetallic compound. The average size of the intermetallic compound decreased as the cooling rate increased. These results suggest that adding nanosize metallic powders may significantly alter and/or improve solder joint properties.
3
Hunt, Emily M., i Pilaka Murty. "Mechanical Properties of NiAl Nanocomposite Intermetallic Alloys With Varying Porosity". W ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-11805.
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Recent advancements in the field of nano-technology focused attention on developing materials with new and useful characteristics. In particular, there is interest in designing nanocomposite thermites for combustion synthesis applications. The composite material consists of nano-scale particles that are in nearly atomic scale proximity but constrained from reaction until triggered. Once initiated, the reaction will become self-sustaining and a new intermetallic alloy product will be produced. An example of this type of reaction is between Ni and Al such that a nickel-aluminide alloy is produced (Eq. (1) [1].
4
Ege, E. S., i Y. L. Shen. "Deformation and Damage in Solder During Fast Cyclic Loading". W ASME 2003 International Electronic Packaging Technical Conference and Exhibition. ASMEDC, 2003. http://dx.doi.org/10.1115/ipack2003-35030.
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Experimental and numerical studies on fast cyclic loading of eutectic tin-lead solder and relevant micromechanical issues are presented. High-frequency twin-lap shear tests on solder joints show cracking inside the solder but often connecting the intruded tips of the intermetallic. Finite element modeling was carried out to study the effect of intermetallic morphology. Without the influence of local phase coarsening, the intrusion of intermetallic into the solder alloy is seen to trigger strain localization which promotes failure. The effect of local phase coarsening was also studied numerically, taking into account the individual phase arrangement. A coarser phase structure always shows a faster accumulation of local plastic strain, leading to early failure. Such results, in agreement with typical thermomechanical fatigue features, cannot be obtained from the traditional argument of strength vs. microstructural size. Modeling of the entire lap-shear specimen was also conducted for the purpose of quantifying the deformation behavior. The exact geometry of solder is found to play a dominant role in affecting the shear response.
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Wang, H. T., C. J. Li, G. J. Yang i C. X. Li. "Formation of Fe-Al Intermetallic Compound Coating Through Cold Spraying". W ITSC2006, redaktorzy B. R. Marple, M. M. Hyland, Y. C. Lau, R. S. Lima i J. Voyer. ASM International, 2006. http://dx.doi.org/10.31399/asm.cp.itsc2006p0157.
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Abstract Intermetallic materials have excellent high temperature oxidation resistance and erosion, cavitation resistances and are promising coating materials with many potential industrial applications. In this study, the formation of Fe-Al intermetallic compound-based coating was performed by cold spraying assisted by a post-annealing treatment. Fe-Al alloy composite powder containing 20wt% WC-Co was produced by ball milling process. Nano-structured Fe-Al alloy coating was deposited through cold spraying. The coating was annealed at different temperatures. The microstructure of the coating was characterized by scanning electron microscopy, optical microscopy and x-ray diffraction analysis. It was found that the microstructure of the as-sprayed coating depended significantly on the microstructure of the powder. A Fe-Al intermetallic phase was formed during the annealing at a temperature higher than 500°C. Moreover, grain growth occurred with the increase of the annealing temperature. The results showed that the microhardness of the as-sprayed coating reached 600HV and more. The effect of the annealing treatment on the coating microstructure and hardness was examined.
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Li, H., H. J. Nie, W. M. Long, S. J. Zhong i Z. Chen. "Application of Cold Spraying for Contact Reactive Brazing of Mg Alloy to Steel". W ITSC 2016, redaktorzy A. Agarwal, G. Bolelli, A. Concustell, Y. C. Lau, A. McDonald, F. L. Toma, E. Turunen i C. A. Widener. DVS Media GmbH, 2016. http://dx.doi.org/10.31399/asm.cp.itsc2016p0201.
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Abstract This study investigates the use of cold gas spraying (CGS) for depositing braze filler coatings. In the experiments, pure Cu layers were sprayed onto Mg alloy substrates, which were then joined to AlSi steel by contact reaction brazing in a vacuum furnace. The bonding temperature influenced the dissolution of Cu as well as the eutectic reaction between the coating and substrate. The thickness of the brazed seam was found to be 300 μm although the initial thickness of the Cu layer was just 50 μm. The shear strength of the joint peaked at 37 MPa, corresponding to a brazing temperature of 530 °C. Intermetallic phases and interfacial defects of various types were responsible for the low strength of the joints.
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Lee, H., H. Shin i K. Ko. "Effects of Gas Pressure of Cold Spray on the Formation of Al Based Intermetallic Compound". W ITSC2009, redaktorzy B. R. Marple, M. M. Hyland, Y. C. Lau, C. J. Li, R. S. Lima i G. Montavon. ASM International, 2009. http://dx.doi.org/10.31399/asm.cp.itsc2009p0302.
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Abstract Post-annealing of cold spray coatings has great potential for wear applications because it produces intermetallic compounds at low temperature far below equilibrium. This study investigates the effects of spraying pressure on the intermetallics formed and their dispersion characteristics. In the experiments, Al and Al-Ni powders were sprayed on Ni and Al substrates at 0.7, 1.5, and 2.5 MPa and a portion of the coating samples were annealed in argon at 500, 550, and 600 °C. Detailed examinations showed that Al particles are subject to peening effects that can interfere with the formation of intermetallic compounds during annealing, but that the effects can be mitigated by controlling gas pressure. Spraying pressure was also found to have an effect on the formation of eutectic pores in Al-Ni composite coatings, with higher pressures corresponding to fewer pores.
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Pang, W., H. C. Man i T. M. Yue. "Laser Surface Coating of Metal Matrix Composite on Ti6Al4V Alloy". W ASME 2003 Heat Transfer Summer Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ht2003-47221.
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Laser surface coating of Mo, WC and Mo-WC powders on the surface of Ti6Al4V alloys using a 2kW Nd-YAG laser was performed. The dilution effect, microstructure, microhardness and wear resistance of the fabricated MMC coating were investigated. With a constant thickness of pre-placed powder, the dilution levels of the alloyed layers were found to be increased with the incident laser power. The fabricated MMC layer was metallurgically bonded to the Ti6Al4V substrate. The microhardness of the fabricated surface layer was found to be inversely proportional to the dilution level. The EDAX and XRD spectra results show that new intermetallic compounds and alloy phases were formed in the laser fabricated layer. With increasing weight percentage content of WC particles in the Mo-WC pre-pasted powder, the microhardness and sliding wear resistance of the laser surface coating were increased by 87% and 150 times respectively as compared with the Ti6Al4V alloy.
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Shi, Jing, i Yachao Wang. "Ultrasonic Fluxless Soldering of Eutectic SnPb and SnAgCu Alloys: A Feasibility Study". W ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-39476.
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Compared with the traditional eutectic SnPb soldering, lead-free soldering has been a focal point for electronics packaging research in order for the industry to meet the regulations on environment protection. By eliminating the lead element from soldering process, the concerns on environmental pollution can be significantly reduced. However, the current lead-free soldering processes usually still require the flux chemicals for promoting wetting. The use of flux chemicals is not environmentally friendly. In this study, motivated by the potential benefits of soldering using ultrasonic energy, we carry out a feasibility study of ultrasonic fluxless soldering experiments on both the regular eutectic SnPb soldering alloy, Sn63Pb37 and the popular SnAgCu alloy, SAC305. By developing the appropriate testing conditions, the solder joints are successfully formed using the dipping ultrasonic soldering method regardless if chemical flux is applied. The effects of soldering time, temperature, and ultrasonic power are investigated. The results from SEM observation and EDS element analysis indicate that the use of chemical flux produces thicker intermetallic compound (IMC) layers for Sn63Pb37 alloy, and a longer soldering time leads to thicker IME layers for both solder alloys. However, a higher soldering temperature may not be beneficial to the growth of IME layer in ultrasonic soldering of SAC305 alloy. However, the driving mechanisms behind the phenomena remain to be investigated in the future.
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Wang, Hua Ming, L. G. Yu, X. X. Li i P. Jiang. "Microstructure and wear resistance of laser-surface-carbonized TiC/TiAl composite coating on a gamma-TiAl intermetallic alloy". W International Symposium on Industrial Lasers, redaktorzy Fuxi Gan, Horst Weber, Zaiguang Li i Qingming Chen. SPIE, 1999. http://dx.doi.org/10.1117/12.361109.
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