Journal articles: 'Powder alloys'

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Lykov, P. A., and L. A. Glebov. "Characteristics of Powders from Different Aluminum Alloys for Additive Technologies Obtained by Gas Atomization." Solid State Phenomena 316 (April 2021): 564–69. http://dx.doi.org/10.4028/www.scientific.net/ssp.316.564.

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Selective laser melting (SLM) is one of the additive manufacturing technologies that allows us to produce complex shape metallic objects from powder feedstock. Al-alloys are very promising materials in selective laser melting. In this paper, atomized metal powders of various aluminum alloys are investigated: 1) deformable alloys АК4, АК6; 2) cast alloys АК9ph, АК12; 3) deformable hardened alloy D16. As a part of the work, the particle shape, particle size distribution and technical characteristics of the powders were investigated, and also the compliance of materials with the requirements of additive technologies (SLM) was determined.

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Pereplyotchikov, E. F. "Plasma-powder surfacing of nickel and cobalt alloys on copper and its alloys." Paton Welding Journal 2015, no. 6 (June 28, 2015): 10–13. http://dx.doi.org/10.15407/tpwj2015.06.02.

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Manfredi, Diego, and Róbert Bidulský. "Laser powder bed fusion of aluminum alloys." Acta Metallurgica Slovaca 23, no. 3 (September 27, 2017): 276. http://dx.doi.org/10.12776/ams.v23i3.988.

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<p class="AMSmaintext">The aim of this study is to analyze and to summarize the results of the processing of aluminum alloys, and in particular of the Al-Si-Mg alloys, by means of the Additive Manufacturing (AM) technique defined as Laser Powder Bed Fusion (L-PBF). This process is gaining interest worldwide thanks to the possibility of obtaining a freeform fabrication coupled with high mechanical strength and hardness related to a very fine microstructure. L-PBF is very complex from a physical point of view, due to the extremely rapid interaction between a concentrated laser source and micrometric metallic powders. This generate very fast melting and subsequent solidification on each layer and on the previously consolidated substrate. The effects of the main process variables on the microstructure and mechanical properties of the final parts are analyzed: from the starting powder properties, such as shape and powder size distribution, to the main process parameters, such as laser power, scanning speed and scanning strategy. Furthermore, some examples of applications for the AlSi10Mg alloy are illustrated.</p>

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Labisz, Krzysztof, and Tomasz Tański. "Laser Surface Treatment of Cast Aluminium-Silicon Alloys." Solid State Phenomena 275 (June 2018): 30–40. http://dx.doi.org/10.4028/www.scientific.net/ssp.275.30.

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The reason of performing the investigations carried out in this work was to investigate the microstructure of the laser treated Al-Si-Cu cast aluminium alloy with the ceramic powder particles using High Power Diode Laser (HPDL) for remelting, and/or alloying. First of all the feeding and distribution of the powder in the surface layer of the alloyed and remelted AlSi7Cu material. Very important issue is the determination of the laser treatment parameters, especially the powder feeding rate, laser power, and scan rate to achieve an enhancement of the layer hardness for ensuring this cast aluminium alloy from losing their working properties and to achieve the tool surface is more resistant to wear. The purpose of this work was also to determine technological and technical conditions comparison for the Al2O3 and SiC ceramic powder alloyed into the surface layer with High Power Diode Laser. There are presented also the investigation results about the determination of proper technical condition during the laser treatment, especially the laser head distance and shielding gas influence. The presented results concerns first of all the structure investigation of the obtained surface layer allowing it to achieve an enhanced hardness and wear resistance more resistant for work, special attention was devoted to monitoring of the layer morphology of the investigated material and on the particle occurred. Light (LM) and scanning electron microscopy (SEM) were used to characterize the microstructure of the obtained surface zones - the remelted zone (RZ) and heat affected zone (HAZ), the ceramic powder distribution and intermetallic phases occurred. A wide range of laser power values was applied and implicated with different laser scan rates. The powders in form of ceramic powders used for alloying were chosen with the particle size of ca. 60μm. This study was conducted to investigate the influence carbide and oxide powder addition on structure and mechanical properties as well the and structure changes occurred during the rapid solidification process. The investigation ensures to use laser treatment for alloying/feeding of ceramic powder particles into the surface of light alloys. The scientific reason of this work is the applying of High Power Diode Laser (HPDL) for improvement of aluminium`s mechanical properties, especially the surface hardness. As the main findings was determined that the obtained surface layer is homogeny without cracks and has a comparably higher hardness value compared to non-treated material. The surface hardness increases together with the applied laser power, the highest power applied gives the highest hardness value for the surface. Also the distribution of the ceramic particles is proper, but there a need for further modelling, because the hardness increases in general according to the laser power used so that the highest power applied gives to highest hardness value in the remelted layer, but for other powder amount or alloy the values should be determined separately, and more data would be necessary to create a model for the technique appliance. The practical purpose of this work is to analysis the impact and application possibility of HPDL laser surface treatment on the cast Al-Si-Cu alloys to deliver application possibilities for diverse branches of industry.

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Ewald, Simon, Fabian Kies, Steffen Hermsen, Maximilian Voshage, Christian Haase, and Johannes Henrich Schleifenbaum. "Rapid Alloy Development of Extremely High-Alloyed Metals Using Powder Blends in Laser Powder Bed Fusion." Materials 12, no. 10 (May 26, 2019): 1706. http://dx.doi.org/10.3390/ma12101706.

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The design of new alloys by and for metal additive manufacturing (AM) is an emerging field of research. Currently, pre-alloyed powders are used in metal AM, which are expensive and inflexible in terms of varying chemical composition. The present study describes the adaption of rapid alloy development in laser powder bed fusion (LPBF) by using elemental powder blends. This enables an agile and resource-efficient approach to designing and screening new alloys through fast generation of alloys with varying chemical compositions. This method was evaluated on the new and chemically complex materials group of multi-principal element alloys (MPEAs), also known as high-entropy alloys (HEAs). MPEAs constitute ideal candidates for the introduced methodology due to the large space for possible alloys. First, process parameters for LPBF with powder blends containing at least five different elemental powders were developed. Secondly, the influence of processing parameters and the resulting energy density input on the homogeneity of the manufactured parts were investigated. Microstructural characterization was carried out by optical microscopy, electron backscatter diffraction (EBSD), and energy-dispersive X-ray spectroscopy (EDS), while mechanical properties were evaluated using tensile testing. Finally, the applicability of powder blends in LPBF was demonstrated through the manufacture of geometrically complex lattice structures with energy absorption functionality.

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Yang, Fei, Brian Gabbitas, Ajit Pal Singh, Stella Raynova, Hui Yang Lu, and Barry Robinson. "Preparation of Titanium Alloy Parts by Powder Compact Extrusion of a Powder Mixture and Scaled up Manufacture." Key Engineering Materials 704 (August 2016): 75–84. http://dx.doi.org/10.4028/www.scientific.net/kem.704.75.

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Blended Elemental Powder Metallurgy (BE-PM) is a very attractive method for producing titanium alloys, which can be near-net shape formed with compositional freedom. However, a minimization of oxygen pick-up during processing into manufactured parts is a big challenge for powder metallurgy of titanium alloys. In this paper, different approaches for preparing titanium alloy parts by powder compact extrusion with 0.05-0.1wt.% of oxygen pick-up during manufacturing are discussed. The starting materials were a powder mixture of HDH titanium powder, other elemental powders and a master alloy powder. Different titanium alloys and composites, such as Ti-6Al-4V, Ti-4Al-4Sn-4Mo-0.5Si, Ti-5Al-5V-5Mo-3Cr, and Ti-5Al-5V-5Mo-3Cr-5vol%TiB, with different profiles such as round and rectangular bars, a wedge profile, wire and tubes have been successfully manufactured on a laboratory and pilot-plant scale. Furthermore, a possible route for scaling up the titanium processing capabilities in the University of Waikato has also been discussed.

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Povarova, K. B., O. A. Skachkov, N. K. Kazanskaya, A. A. Drozdov, A. E. Morozov, and O. N. Makarevich. "NiAl powder alloys: I. Production of NiAl powders." Russian Metallurgy (Metally) 2011, no. 9 (September 2011): 844–52. http://dx.doi.org/10.1134/s0036029511090199.

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Radev, D. D. "Nickel-Containing Alloys for Medical Application Obtained by Methods of Mechanochemistry and Powder Metallurgy." ISRN Metallurgy 2012 (November 14, 2012): 1–6. http://dx.doi.org/10.5402/2012/464089.

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The methods of mechanochemistry, in combination with cold pressing and pressureless sintering, were used to obtain the most popular nickel-based and nickel-containing alloys used in dentistry and implantology. It was shown that the intense mechanical treatment of Ni, Ti, and Cr powders used as reagents, and the application of the above-mentioned simple powder metallurgical technique for densification allows obtaining NiCr and NiTi alloys with controlled structural properties. The nickel-based dental alloys obtained by mechanically activated sintering possess excellent mechanical, technological, and aesthetic properties. These alloys are suitable as dental restorative materials and for production of porcelain veneered constructions like crowns and bridges using the so-called metal-to-ceramic dental technique. It was shown that the method of mechanically assisted synthesis allows obtaining nanosized NiTi alloy at significantly lower temperature in comparison with the traditional high-temperature alloying. It was also shown that after 40 hours intense mechanical treatment of reagents, a direct synthesis of NiTi alloy proceeds. The product has excellent sinterability which enables to produce bodies with controlled porosity appropriate for application in implantology.

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Znamenskii, L. G., A. N. Franchuk, and A. A. Yuzhakova. "Nanostructured Materials in Preparation Casting Alloys." Materials Science Forum 946 (February 2019): 668–72. http://dx.doi.org/10.4028/www.scientific.net/msf.946.668.

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The article deals with technologies of refining and inoculating casting alloys with the use of nanostructured diamond powder, as well as stimulation technique on molten metal including processing of the liquid alloy with nanosecond electromagnetic pulses. The developed method of cast iron inoculation allows to eliminate the flare and to increase the physical and mechanical properties of the castings through the grain refining and the decrease of chilling tendency during crystallization of the liquid alloy. Inoculating of aluminium alloys by high-melting particles of a nanostructured diamond powder leads to the grinding of structural constituents, including conditions for dispersing hardening intermetallics during postbaking of such castings. As a result, foundry and physicomechanical properties of castings are significantly improved.

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Stráský, J., J. Kozlík, K. Bartha, D. Preisler, and T. Chráska. "Sintering of Ti-based biomedical alloys with increased oxygen content from elemental powders." MATEC Web of Conferences 321 (2020): 05010. http://dx.doi.org/10.1051/matecconf/202032105010.

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Revived interest for beta Ti alloys with increased oxygen content is motivated by the prospect of achieving material with low modulus and high strength simultaneously. Fine tuning of amount of oxygen and beta stabilizing elements is critical for achieving good mechanical properties. This study shows that powder metallurgy method of spark plasma sintering is capable of producing Ti-Nb-Zr-O alloys from elemental powders. This simple approach allows for quick sampling and production of several alloys with various chemical composition. Elemental powders were mixed with appropriate amount of titanium dioxide to achieve Ti-29Nb-7Zr-0.7O alloy. Sintering was performed at 1400 - 1500 °C for 15 – 30 minutes.

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Huang, Gonghao, Zefeng Fan, Liu Li, Yanjin Lu, and Jinxin Lin. "Corrosion Resistance of Selective Laser Melted Ti6Al4V3Cu Alloy Produced Using Pre-Alloyed and Mixed Powder." Materials 15, no. 7 (March 28, 2022): 2487. http://dx.doi.org/10.3390/ma15072487.

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Metallic elemental powder mixture and pre-alloyed metallic powder are both frequently used powder feedstock in the additive manufacturing process. However, little research has been conducted to compare the corrosion behavior of selective laser melting (SLM) alloys, fabricated by pre-alloyed metallic powder and mixed metallic powder. Hence, it is important to investigate the corrosion behavior of SLMed alloys, as well as the corresponding cast ingot, with the aim to better understand the feasibility of designing new materials. In this work, the SLM-produced Ti6Al4V3Cu alloys were manufactured using a metallic elemental powder mixture and pre-alloyed metallic powder, respectively. The corrosion behavior of the different Ti6Al4V3Cu alloys was investigated in following electrochemical tests and ion release measurements. The results showed that the Ti6Al4V3Cu alloy prepared by pre-alloyed metallic powder showed better corrosion resistance than that produced from mixed metallic powder. Moreover, the SLM-produced Ti6Al4V3Cu alloys performed significantly better in corrosion resistance than the cast Ti6Al4V3Cu. The results are expected to achieve a better understanding of the feasibility of designing new materials using mixed powders, contributing to reducing development costs and cycles.

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Wolff, Martin, Carsten Blawert, Michael Dahms, and Thomas Ebel. "Properties of Sintered Mg Alloys for Biomedical Applications." Materials Science Forum 690 (June 2011): 491–94. http://dx.doi.org/10.4028/www.scientific.net/msf.690.491.

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In addition to the use as light weight construction material, magnesium alloys are also very suitable for future orthopaedic and traumatology applications. Common permanent implant materials such as titanium or stainless steel still suffer from stress shielding problems, causing bone resorption and implant loosening. In contrast, magnesium alloys provide elastic moduli and strengths matching those of cortical bone. In order to support osseointegration and vascularisation, an open porous surface structure of an Mg-implant is advantageous. The powder metallurgical processing route of Mg-alloys enables the generation of such parts. Powder blends with different sintering behaviour were produced via mixing pure Mg-powder with different Ca containing master alloy powders (MAP). As a result, sintering of these Mg alloy powders and blends became feasible. Sintered parts were investigated in view of shrinkage, porosity, grain size using SEM, EDX and XRD. In addition, compression tests were performed revealing ultimate compression strength up to 328 MPa, plastic compressibility of 22 % and compressive yield strength up to 90 MPa. Hence, the PM-route enables the production of parts with mechanical properties matching those of cortical bone.

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Hinrichs, Frauke, Alexander Kauffmann, Daniel Schliephake, Sascha Seils, Susanne Obert, Karin Ratschbacher, Melissa Allen, Astrid Pundt, and Martin Heilmaier. "Flexible Powder Production for Additive Manufacturing of Refractory Metal-Based Alloys." Metals 11, no. 11 (October 28, 2021): 1723. http://dx.doi.org/10.3390/met11111723.

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The quality and properties of metal powders are essential for powder metallurgical (PM) processes in general and for additive manufacturing (AM) processing routes in particular. Thus, a variety of atomization technologies were established meeting the multiple needs of the different processing technologies. However, the production of refractory metal alloy powder remains challenging due to their high liquidus temperatures (>2000 °C), the formation of brittle intermetallic phases, as well as the reactivity with and sensitivity to interstitials of the constituting elements. In this contribution, powders made of Mo-20Si-52.8-Ti (at.%) were produced by a novel ultrasonic atomization (UA) process at laboratory-scale using an industrial electrode induction gas atomization (EIGA) process with a modified electrode concept for the first time. UA allows flexibility in alloy composition due to the arc melting-based principle, while the EIGA electrode is PM manufactured from elemental powders to provide similar flexibility on a larger scale. The powders resulting from these two processes were compared with respect to size distribution, sphericity, microstructure and phase constitution, chemical composition, and interstitial impurity content. In addition, several powder batches were produced with the UA process in order to assess the process reliability and stability. The properties, quality, and quantities of UA powders perfectly meet the requests for alloy development for powder bed fusion AM, while the modified EIGA process allows the upscaling of the alloy powder quantities.

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Bolzoni, L., E. M. Ruiz-Navas, De Liang Zhang, and Elena Gordo. "Modification of Sintered Titanium Alloys by Hot Isostatic Pressing." Key Engineering Materials 520 (August 2012): 63–69. http://dx.doi.org/10.4028/www.scientific.net/kem.520.63.

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Powder metallurgy (PM) permits to obtain titanium alloys with properties and microstructures close to ingot metallurgy products. However, residual porosity is normally present in the products produced by the PM route of powder pressing and sintering (P&S)\, and this needs to be reduced by using post-sintering process step such as hot isostatic pressing (HIP) and forging. In this study, the microstructural and mechanical property changes caused by HIP of samples of two alloys, near-α Ti-3Al-2.5V alloy and α+β Ti-6Al-4V, produced by P&S route were investigated. Two types of powders were utilised: prealloyed powders and blend of elemental titanium powder and master alloy powder. Four conditions defined by HIP temperature, pressure and time were used to HIP the sintered samples with two geometries. The results show that, independent of the HIP conditions used, HIP increased the relative density of the samples to approximately 97.5% and their hardness by 30-50 HV depending on the HIP condition. However, HIP at 1000°C changes the fracture mode of the sintered samples from ductile to brittle.

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Raynova, Stella, Brian Gabbitas, Leandro Bolzoni, and Fei Yang. "Development of Low Cost PM Ti Alloys by Thermomechanical Processing of Powder Blends." Key Engineering Materials 704 (August 2016): 378–87. http://dx.doi.org/10.4028/www.scientific.net/kem.704.378.

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This research focuses on the development of low cost powder metallurgy (PM) Ti alloys suitable for application in PM thermomechanical processing with mechanical properties comparable to those of wrought Ti6Al4V alloy. The alloy systems studied are Ti3Al2V, Ti5Fe and Ti3.2Fe1Cr0.6Ni0.1Mo (Ti5SS). The alloy mixtures were produced by blending Ti HDH powders with Al40V, 316SS master alloy powders or elemental Fe powder. The blended powders were further consolidated using various methods: high vacuum sintering (HVS), induction sintering (IS), powder compact forging (PCF) and powder compact extrusion (PCE). It is found that, PM Ti3Al2V and Ti5Fe alloy processed by PCE or PCF followed by recrystallization annealing (RA) achieved tensile properties comparable with wrought Ti6Al4V alloy. Tensile properties such as yield strength (YS) of 910MPa, UTS of 1010MPa and 15% elongation to fracture for Ti3Al2V alloy are reported. Ti5Fe alloy gives YS and UTS of 870MPa and 968MPa respectively, combined with 20.3% elongation to fracture. The tensile results are related to the microstructure developed during the consolidation processes. The oxygen contamination as a result of the high temperature processing is also reported.

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Minasyan, Tatevik, and Irina Hussainova. "Laser Powder-Bed Fusion of Ceramic Particulate Reinforced Aluminum Alloys: A Review." Materials 15, no. 7 (March 27, 2022): 2467. http://dx.doi.org/10.3390/ma15072467.

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Aluminum (Al) and its alloys are the second most used materials spanning industrial applications in automotive, aircraft and aerospace industries. To comply with the industrial demand for high-performance aluminum alloys with superb mechanical properties, one promising approach is reinforcement with ceramic particulates. Laser powder-bed fusion (LPBF) of Al alloy powders provides vast freedom in design and allows fabrication of aluminum matrix composites with significant grain refinement and textureless microstructure. This review paper evaluates the trends in in situ and ex situ reinforcement of aluminum alloys by ceramic particulates, while analyzing their effect on the material properties and process parameters. The current research efforts are mainly directed toward additives for grain refinement to improve the mechanical performance of the printed parts. Reinforcing additives has been demonstrated as a promising perspective for the industrialization of Al-based composites produced via laser powder-bed fusion technique. In this review, attention is mainly paid to borides (TiB2, LaB6, CaB6), carbides (TiC, SiC), nitrides (TiN, Si3N4, BN, AlN), hybrid additives and their effect on the densification, grain refinement and mechanical behavior of the LPBF-produced composites.

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Zhou, Ziyi, Feng Zhang, Jili Wu, Jinhong Pi, and Fei Chen. "Laser Beam Welding of Feconicrmn High-Entropy Alloys with Preplaced Powders." Metals 10, no. 11 (October 22, 2020): 1402. http://dx.doi.org/10.3390/met10111402.

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In this paper, as-annealed FeCoNiCrMn plates were laser-welded with preplaced FeCoNiCrMn and FeCoNiCrAl powders, respectively. The grains in the fusion zone of the weld with FeCoNiCrMn powder have a reduced aspect ratio compared to those without preplaced powders and the weld with FeCoNiCrAl powder presents relative equiaxed grains. The yield strength of each weld has been remarkably enhanced when referring to the base alloy, and the ultimate tensile strength of each weld with preplaced powder exceeds 80% of that of the base and the maximum reaches 88.5% when referring to the weld with preplaced FeCoNiCrMn powder. Cleavage fractography was observed in the welds. The finding of this work will service the engineering practices of high-entropy alloys.

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Tokaji, Keiro, Yoshihiko Uematsu, and Mitsutoshi Kamakura. "Effect of Powder Size on Fatigue Behaviour in Mg₂Si-Dispersed Magnesium Alloys Produced by Solid-State Synthesis." Key Engineering Materials 345-346 (August 2007): 315–18. http://dx.doi.org/10.4028/www.scientific.net/kem.345-346.315.

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The fatigue behaviour of newly developed Mg2Si-dispersed magnesium (Mg) alloys produced by solid-state synthesis was studied. Rotary bending fatigue tests have been performed using smooth specimens of materials produced with fine and coarse AZ31 alloy powders. Both Mg2Si-dispersed Mg alloys exhibited lower fatigue strength than a conventional extruded AZ31 alloy and the powder size dependence of fatigue strength was clearly recognized, where the material produced with fine alloy powder showed considerably higher fatigue strength than the counterpart. Fatigue cracks invariably initiated at large Mg2Si particles immediately after cyclic loading was applied and subsequent small crack growth was faster than the extruded AZ31 alloy. It was concluded that the lower fatigue strength of Mg2Si-dispersed Mg alloys was attributed to premature crack initiation at Mg2Si particles and faster small crack growth, and the observed powder size dependence of fatigue strength was due to difference in the size of the particle from which the crack initiated.

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Yang, Fei, Brian Gabbitas, Stiliana Raynova, Ajit Pal Singh, and Leandro Bolzoni. "Preparation of Ti-5553 Alloy by Different Extrusion Processes from Elemental Powder Mixtures." Key Engineering Materials 770 (May 2018): 31–38. http://dx.doi.org/10.4028/www.scientific.net/kem.770.31.

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Ti-5553 (Ti-5Al-5V-5Mo-3Cr, wt. %) alloy is a recently developed near β titanium alloy and it has a very good hardenability, good ductility and high strength. In this study, we discussed the feasibility of preparing Ti-5553 alloy by different processes from powder mixtures of hydride-dehydride titanium powder, elemental powders and master alloy powders, including (1) direct extrusion of powder compact in argon, (2) extrusion of the vacuum-sintered billet in air and (3) extrusion of the hot-pressed billet in air. XRD, OM and SEM were used to determine the phase constitutions and microstructures of the prepared Ti-5553 alloys, and mechanical test was performed to examine their mechanical properties. The results showed the microstructures and phase constitutions of Ti-5553 alloys were significantly affected by different processes, which resulted in the relevant mechanical properties. The effect of the selected heat treatment on the microstructures and properties of Ti-5553 alloy were investigated as well.

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Takeda, Yoshinobu, Yusuke Odani, and Tetsuya Hayashi. "Powder metallurgy of aluminum alloys." Bulletin of the Japan Institute of Metals 27, no. 10 (1988): 789–96. http://dx.doi.org/10.2320/materia1962.27.789.

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Froes, F. H., and D. Eylon. "Powder metallurgy of titanium alloys." International Materials Reviews 35, no. 1 (January 1990): 162–84. http://dx.doi.org/10.1179/095066090790323984.

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Farquhar, Lucy, George Maddison, Liam Hardwick, Frances Livera, Iain Todd, and Russell Goodall. "In-Situ Alloying of CoCrFeNiX High Entropy Alloys by Selective Laser Melting." Metals 12, no. 3 (March 8, 2022): 456. http://dx.doi.org/10.3390/met12030456.

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High Entropy Alloys are a class of alloys which have been shown to largely exhibit stable microstructures, as well as frequently good mechanical properties, particularly when manufactured by additive manufacturing. Due to the large number of potential compositions that their multi-component nature introduces, high throughput alloy development methods are desirable to speed up the investigation of novel alloys. Here, we explore once such method, in-situ alloying during Additive Manufacture, where a powder of a certain pre-alloyed composition is mixed with the required composition of powder of an additional element, such that alloying takes place when powders are melted during the process. To test the effectiveness and capability of the approach, selective laser melting has been used to manufacture pre-alloyed CoCrFeNi, and also CoCrFeNiCu and CoCrFeNiTi alloys by combining pre-alloyed CoCrFeNi powder with elemental powders of Cu and Ti. Processing parameter variations are used to find the highest relative density for each alloy, and samples were then characterised for microstructure and phase composition. The CoCrFeNi alloy shows a single phase face centred cubic (FCC) microstructure, as found with other processing methods. The CoCrFeNiCu alloy has a two phase FCC microstructure with clear partitioning of the Cu, while the CoCrFeNiTi alloy has an FCC matrix phase with NiTi intermetallics and a hexagonal close packed (HCP) phase, as well as unmelted Ti particles. The microstructures therefore differ from those observed in the same alloys manufactured by other methods, mainly due to the presence of areas with higher concentrations than usually encountered of Cu and Ti respectively. Successful in-situ alloying in this process seems to be improved by the added elemental powder having a lower melting point than the base alloy, as well as a low inherent tendency to segregate. While not producing directly comparable microstructures however, the approach does seem to offer advantages for the rapid screening of alloys for AM processability, identifying, for example, extensive solid-state cracking in the CoCrFeNiTi alloy.

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Sorcoi, L. Adriana. "Mechanical and Technological Properties of Sintered Cu90Ni10 Compacts." Advanced Materials Research 23 (October 2007): 75–78. http://dx.doi.org/10.4028/www.scientific.net/amr.23.75.

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This paper presents Cu90Ni10 alloy properties. These alloys were produced in three distinct modes: alloyed powders (P), powder made from elemental powders of copper and nickel (A); powders from the Cu80Ni20 alloy and an alloying element (D). The influence of time, composition and properties of the powder mixture upon the final properties of the sintered alloys was studied. A comparative study of the sintered compacts obtained by varying the parameters of procedure, compacting pressure and sintering time was performed. The work aimed to research the influence of the parameters above mentioned: density, compressibility, structure of compacts, etc. The sintering capacity was also assessed through the resistence to fracture and hardness of samples, also versus the parameters above mentioned.

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Ivasishin, Orest M., Daniel Eylon, V. I. Bondarchuk, and Dmytro G. Savvakin. "Diffusion during Powder Metallurgy Synthesis of Titanium Alloys." Defect and Diffusion Forum 277 (April 2008): 177–85. http://dx.doi.org/10.4028/www.scientific.net/ddf.277.177.

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In the present study titanium alloys were synthesized by the blended elemental press-andsinter powder metallurgy approach using hydrogenated titanium powder. Experimental investigation and modeling of the homogenization processes during synthesis were used to analyze peculiarities of mass transfer and factors affecting diffusion. Processes of alloying elements redistribution during chemical homogenization of powder blends are shown to be strongly dependent on the chemical composition of the initial powders. Optimization of the processing parameters allows to synthesize uniform, nearly-dense material with reduced grain size, at relatively low temperatures and short time. This will provide improvement of mechanical properties simultaneously with better cost-effectiveness of the process.

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Ridolfi, Maria Rita, Paolo Folgarait, and Andrea Di Schino. "Laser Operating Windows Prediction in Selective Laser-Melting Processing of Metallic Powders: Development and Validation of a Computational Fluid Dynamics-Based Model." Materials 13, no. 6 (March 20, 2020): 1424. http://dx.doi.org/10.3390/ma13061424.

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The rapidly ascending trend of additive manufacturing techniques requires a tailoring of existing solidification models and the development of new numerical tools. User-friendly numerical models can be a valid aid in order to optimize operating parameter ranges with the scope to extend the modelling tools to already existing or innovative alloys. In this paper a modelling approach is described simulating the generation of single tracks on a powder bed system in a selective laser melting process. The approach we report attains track geometry as a function of: alloy thermo-physical properties, laser speed and power, powder bed thickness. Aim of the research is to generate a numerical tool able to predict laser power and speed ranges in manufacturing porosity-free printed parts without lack of fusion and keyhole pores. The approach is based on a simplified description of the physical aspects. Main simplifications concern: the laser energy input, the formation of the pool cavity, and the powder bed thermo-physical properties. The model has been adjusted based on literature data providing the track’s geometry (width and depth) and relative density. Such data refer to different alloys. In particular, Ti6Al4V, Inconel625, Al7050, 316L and pure copper are considered. We show that the printing process presents features common to all alloys. This allows the model to predict the printing behavior of an alloy from its physical properties, avoiding the need to perform specific experimental activities.

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Kirchner, Alexander, Burghardt Klöden, Marie Franke-Jurisch, Gunnar Walther, and Thomas Weißgärber. "Electron Beam Powder Bed Fusion of Water Atomized Iron and Powder Blends." Materials 15, no. 4 (February 19, 2022): 1567. http://dx.doi.org/10.3390/ma15041567.

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In the present state of the art, highly spherical alloy powders are employed as feedstock in powder bed fusion processes. These powders are characterized by high flowability and apparent density. Their elaborate fabrication process is reflected in high powder price, adding a significant fraction to the cost of additively manufactured parts. Thus, the use of non-spherical powders, such as water atomized material, can lower costs significantly. Here, the electron beam powder bed fusion (PBF-EB) of standard water atomized iron powder used for press-and-sinter is studied. Despite raking problems, using the coating mechanism in standard configuration samples with densities exceeding 99% were fabricated. In a further step, the addition of alloying elements by powder blending is explored. Important powder properties of feedstock blended from irregular and spherical powders are characterized. The PBF-EB processing of two alloys is presented. The first represents a low carbon steel. Samples were characterized by metallographic cross-section, energy dispersive X-ray (EDX) mapping, and mechanical testing. The second alloy system is a FeCrAl. After PBF-EB processing of the powder mixture, chemical homogeneity was achieved. Besides the low cost, this approach of using water atomized powder mixed with master alloy offers the advantage of high flexibility for potential application.

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Stanciulescu, Madalina, Marioara Abrudeanu, Andrei Galatanu, Paula Carlan, and Maria Mihalache. "Dissolution Behaviour of Alloying Elements Into Vanadium Matrix During Mechanical Milling." Revista de Chimie 68, no. 5 (June 15, 2017): 1109–13. http://dx.doi.org/10.37358/rc.17.5.5622.

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Mechanical alloying (MA) is an efficient approach for fabricating ODS alloys and structural materials including vanadium alloys for fusion and fission applications. Dissolution behavior of the alloying elements is a key issue for optimizing the mechanical alloying process in fabricating vanadium alloys. This paper studies the MA process of V-4wt.%Cr-4wt.%Ti alloy. The outcomes of the MA powders in a planetary ball mill are reported in terms of powder particle size, morphology and composition evolution. The impact of spark-plasma sintering process on the mechanically alloyed powder is analyzed. The microstructure of the V-4wt.%Cr-4wt.%Ti alloy prepared by mechanical milling is investigated with a X-ray diffractometer and scanning electron microscope.

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Svetlizky, David, Honorata Kazimierczak, Bar Ovadia, Ariel Sharoni, and Noam Eliaz. "Electrochemical Processing and Thermal Properties of Functional Core/Multi-Shell ZnAl/Ni/NiP Microparticles." Materials 14, no. 4 (February 9, 2021): 834. http://dx.doi.org/10.3390/ma14040834.

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Electroless deposition on zinc and its alloys is challenging because of the negative standard potential of zinc, the formation of poor surface layers during oxidation in aqueous solutions, and extensive hydrogen evolution. Therefore, there are only few reports of electroless deposition on Zn and its alloys, neither of them on micro/nano powders. Here, we propose a two-step process that allows the formation of compact, uniform, and conformal Ni/NiP shell on Zn-based alloy microparticles without agglomeration. The process utilizes controlled galvanic displacement of Ni deposition in ethanol-based bath, followed by NiP autocatalytic deposition in an alkaline aqueous solution. The mechanism and effect of deposition conditions on the shell formation are discussed. Thermal stability and functional analysis of core-shell powder reveal a thermal storage capability of 98.5% with an encapsulation ratio of 66.5%. No significant morphological change of the core-shell powder and no apparent leakage of the ZnAl alloy through the Ni shell are evident following differential scanning calorimetry tests. Our two-step process paves the way to utilize electroless deposition for depositing metallic-based functional coatings on Zn-based bulk and powder materials.

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Guilherme, Eneida da G., H. R. Hechenberg, and José Octavio A. Pascoal. "Reduction-Diffusion Preparation of Nd₁₅Fe₇₇B₈, NdFe₁₁Ti, NdFe_10.5Mo_1.5 and NdFe_10.75Mo_1.25 Alloys for Magnets." Materials Science Forum 530-531 (November 2006): 181–86. http://dx.doi.org/10.4028/www.scientific.net/msf.530-531.181.

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The calciothermic reduction-diffusion (CRD) process is a alternative preparation route for Nd15Fe77B8, NdFe11Ti, NdFe10.5Mo1.5 and NdFe10.75Mo1.25 alloys, which eliminates the need for long homogenizing heat treatment; in addition, the resulting alloy is already in powder form. We have examined the effect of various processing variables in the preparation of mother alloys. Compacts made of NdCl3, Fe, Ti, Mo and Fe-B powders and Ca granules were heated under argon for different times and temperatures. The alloys as-prepared contained mostly the hard magnetic phase. The NdFe11Ti, NdFe10.75Mo1.25 and NdFe10.5Mo1.5 alloys have been successfully nitrogenated by heating a mixture of powdered alloys with sodium azide (NaN3) at temperatures between 330 and 450 oC.

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Wendhausen, Paulo A. P., Aline Silva, André L. Slaviero, and Ricardo Machado. "On the Use of Elemental Powders to Process Fe-50Co Alloys by Powder Injection Molding." Materials Science Forum 530-531 (November 2006): 230–35. http://dx.doi.org/10.4028/www.scientific.net/msf.530-531.230.

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Aiming to obtain components with higher density, this work evaluated the technical and economical viabilities to replace the pre-alloyed Fe49Co2V by an elemental powder alloy of iron and cobalt (Fe-50Co). Using an elemental alloy could increase the density of the final material due to the driving force created by the chemical gradient between the powders. The results showed that is possible to achieve higher densities in an elemental powder Fe-50Co alloy sinterized at the same temperature and in shorter times than the Fe49Co2V alloy. The analysis of economical viability showed that the replacement of the alloys have advantages as the pre-alloyed powder price is higher than the elemental.

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Manne, Pradeep Kumar, Nutenki Shravan Kumar, Tanya Buddi, A. Anitha Lakshmi, and Ram Subbiah. "Powder Metallurgy Techniques for Titanium Alloys-A Review." E3S Web of Conferences 184 (2020): 01045. http://dx.doi.org/10.1051/e3sconf/202018401045.

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Powder metallurgy (PM) is a technique in which materials or components are made from metal powders. In this paper, the overview about titanium alloys and their advantages over engineering applications has been discussed. They are very strong and also possess great mechanical properties and incredible corrosion and wear resistance, and also capable of performing operations at elevated temperatures approximately up to 600ºC. This paper provides various compositions of titanium alloys and various powder metallurgy techniques used for sintering powders of various compositions and their applications. The properties of titanium compounds show the manufacturing of cost effective component. As a result of their fantastic mechanical, physical and organic execution they are finding consistently expanding application in biomedical applications.

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Miura, Yuki, Yasuyuki Kaneno, Takayuki Takasugi, and Atsushi Kakituji. "Characterization of Ni3(Si,Ti) intermetalic alloys synthesized by powder metallurgical method." MRS Proceedings 1516 (2013): 121–26. http://dx.doi.org/10.1557/opl.2013.109.

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ABSTRACTA Ni3(Si,Ti) intermetalic alloy was synthesized by the powder metallurgy method using elemental powders. The raw powder mixtures with various compositions were sintered by a spark plasma sintering apparatus and then homogenized at high temperatures. Microstructure, hardness, tensile properties and density of the sintered alloys were investigated as functions of the chemical composition and sintering temperature. It was found that a highly-densified Ni3(Si,Ti) sintered alloy was obtained by choosing proper chemical composition and sintering temperature. Also, the Ni3(Si,Ti) sintered alloy with an L12 single-phase microstructure exhibited high hardness and tensile strength.

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Huang, Sheng, Dichen Li, Lianzhong Zhang, Xiaoyu Zhang, and Weijun Zhu. "Tailoring the Mechanical Properties of Laser Cladding-Deposited Ferrous Alloys with a Mixture of 410L Alloy and Fe–Cr–B–Si–Mo Alloy Powders." Materials 12, no. 3 (January 29, 2019): 410. http://dx.doi.org/10.3390/ma12030410.

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The effects of different ratios of 410L alloy and Fe–Cr–B–Si–Mo alloy powders on the microstructure and mechanical properties of laser cladding-deposited ferrous alloys were investigated. The experimental results revealed that the 410L alloy had good strength and excellent ductility due to its microstructure consisting of large elongated ferrite dendrites surrounded by a small number of martensite grains, while the Fe–Cr–B–Si–Mo alloy had high strength and poor ductility because of its eutectic microstructure composed of ferrite and Fe2B/Cr2B. As the concentration of Fe–Cr–B–Si–Mo alloy powder added to the 410L alloy powder increased, the ferrite grains became finer and the volume fraction of the eutectic increased, which eventually improved the strength and reduced the plasticity. Then, 410L + 12.5% Fe–Cr–B–Si–Mo alloy powder was successfully deposited onto AISI 1060 steel substrate via laser cladding deposition, and the mechanical properties met those of the substrate, which verified that tailoring the mechanical properties of the laser cladding-deposited alloys with a mixture of 410L and Fe–Cr–B–Si–Mo alloy powders for steel repairing applications is a feasible solution.

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Chen, Yitao, Xinchang Zhang, Mohammad Masud Parvez, and Frank Liou. "A Review on Metallic Alloys Fabrication Using Elemental Powder Blends by Laser Powder Directed Energy Deposition Process." Materials 13, no. 16 (August 12, 2020): 3562. http://dx.doi.org/10.3390/ma13163562.

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The laser powder directed energy deposition process is a metal additive manufacturing technique, which can fabricate metal parts with high geometric and material flexibility. The unique feature of in-situ powder feeding makes it possible to customize the elemental composition using elemental powder mixture during the fabrication process. Thus, it can be potentially applied to synthesize industrial alloys with low cost, modify alloys with different powder mixtures, and design novel alloys with location-dependent properties using elemental powder blends as feedstocks. This paper provides an overview of using a laser powder directed energy deposition method to fabricate various types of alloys by feeding elemental powder blends. At first, the advantage of laser powder directed energy deposition in manufacturing metal alloys is described in detail. Then, the state-of-the-art research and development in alloys fabricated by laser powder directed energy deposition through a mix of elemental powders in multiple categories is reviewed. Finally, critical technical challenges, mainly in composition control are discussed for future development.

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Palacios-Lazcano, A. F., J. L. Luna-Sánchez, J. Jiménez-Gallegos, Francisco Cruz-Gandarilla, and J. Gerardo Cabañas-Moreno. "Hydrogen Storage in Nanostructured Mg-Base Alloys." Journal of Nano Research 5 (February 2009): 213–21. http://dx.doi.org/10.4028/www.scientific.net/jnanor.5.213.

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Powders of elemental Mg, Zn, Al and Ag were milled in order to produce nanocrystalline alloys with nominal composition Mg98M2 (M=Zn, Al and Ag). Pure Mg was also mechanically milled without any additions. Single-phase nanocrystalline (crystal size 24-26 nm) Mg98M2 alloys were produced after 216 ks of milling. A passivity procedure was followed immediately after milling, by gradually exposing the alloy powders to air (~ 12 hrs). After this procedure, the mechanically alloyed powders were kept under argon atmosphere before being hydrided at 200 and 300 °C under 0.5 and 3 MPa P for 10 min. Previously milled (~ 1.5 years before) and passivated powder alloys (stored in air and referred to as “AE” samples) were also hydrided under the same conditions. No hydriding was observed in the as-received Mg powders (crystal size >> 100 nm), but the as-milled, passivated nanocrystalline alloys were partially hydrided (even the AE samples). The amounts of the MgH2 phase in the hydrided samples were larger in the Ar-stored than in the AE samples under all hydriding conditions. The possible role of MgO and Mg hydroxides, as well as of the alloying elements, on the hydriding behavior of the nanostructured, mechanically alloyed powder alloys is discussed.

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Ivasishin, O. M., D. G. Savvakin, D. V. Oryshych, O. O. Stasiuk, and Li Yuanyuan. "Hydride Approach in Blended Elemental Powder Metallurgy of Beta Titanium Alloys." MATEC Web of Conferences 321 (2020): 03009. http://dx.doi.org/10.1051/matecconf/202032103009.

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The physical bases of hydrogenated titanium powders application in blended elemental powder metallurgy (BEPM) of titanium alloys were earlier developed. Hydrogen as temporary alloying addition for titanium strongly affects diffusion processes upon transformation of powder blends into alloys ensuring production of α+β and metastable β titanium alloys which mechanical properties meet standard requirements. At the same time, synthesis of metastable β alloys is complicated by a big amount of alloying elements which diffusion redistribution upon sintering has a strong impact on microstructure evolution. In present study BEPM hydride approach was expanded for production of biocompatible low modulus Ti-Zr-Nb and Ti-Zr-Nb-Ta alloys having BCC structure which are attractive materials for medical application. The alloys of prescribed compositions were produced using various starting powders, including TiH2, ZrH2, hydrogenated niobium, tantalum and Ti-Nb master alloys. Peculiarities of volume changes of multicomponent powder blends on dehydrogenation were investigated. The specific volume changes of powder components during dehydrogenation affect densification kinetic of powder blends and microstructure of as-sintered alloys.

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Pereloma, Elena V., Dmytro G. Savvakin, Andrew Carman, Azdiar A. Gazder, and Orest M. Ivasishin. "Microstructure Development and Alloying Elements Diffusion during Sintering of Near-β Titanium Alloys." Key Engineering Materials 520 (August 2012): 49–56. http://dx.doi.org/10.4028/www.scientific.net/kem.520.49.

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Two near-β alloys, Ti-5Al-5Mo-5V-2Cr-1Fe and Ti-10V-3Fe-3Al, were produced by the blended element powder metallurgy technique. The use of (i) elemental powders with the Al-V master alloy in the case of Ti-5Al-5Mo-5V-2Cr-1Fe and, (ii) the complex Al-Fe-V master alloy in Ti-10V-3Fe-3Al has highlighted the influence of different alloying elements and their combination on microstructure evolution and chemical homogenisation. While Fe has the fastest diffusivity in Ti and its addition improves the density of both sintered alloys it also results in accelerated rates of grain coarsening. The combination of Al and V in the master alloy powder inhibits the diffusion of V into the Ti matrix. The unexpectedly slow diffusion of Cr at the early sintering stage in Ti-5Al-5Mo-5V-2Cr-1Fe was attributed to the formation of surface oxides on the Cr powders.

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Lindström, Viktor, Oleksii Liashenko, Kai Zweiacker, Serhii Derevianko, Vladyslav Morozovych, Yurij Lyashenko, and Christian Leinenbach. "Laser Powder Bed Fusion of Metal Coated Copper Powders." Materials 13, no. 16 (August 7, 2020): 3493. http://dx.doi.org/10.3390/ma13163493.

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Laser powder bed fusion (L-PBF) of copper alloys with high copper content is difficult due to the high infrared reflectivity and thermal conductivity of these alloys. In this study a simple and scalable method for coating copper powder with tin and nickel is presented, and suggested as an alloying strategy for such alloys. The coated powders were processed in a commercial L-PBF-machine at various scanning speeds. The samples made from coated powders show a lower amount of porosity compared to samples made from in-situ alloyed powders of similar composition.

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Singh, Ajit Pal, Brian Gabbitas, and De Liang Zhang. "Fracture Toughness of Powder Metallurgy and Ingot Titanium Alloys – A Review." Key Engineering Materials 551 (May 2013): 143–60. http://dx.doi.org/10.4028/www.scientific.net/kem.551.143.

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Powder metallurgy (PM) is potentially capable of producing homogeneous titanium alloys at relative low cost compared to ingot metallurgy (IM). There are many established PM methods for consolidating metal powders to near net shapes with a high degree of freedom in alloy composition and resulting microstructural characteristics. The mechanical properties of titanium and its alloys processed using a powder metallurgical route have been studied in great detail; one major concern is that ductility and toughness of materials produced by a PM route are often lower than those of corresponding IM materials. The aim of this paper is to review the fracture toughness of both PM and IM titanium alloys. The effects of critical factors such as interstitial impurities, microstructural features and heat treatment on fracture toughness are also discussed

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Takata, Naoki, Keisuke Uematsu, and Makoto Kobashi. "Porous Ti–Al Intermetallic Based Alloys Fabricated by Pressure-Sintering Elemental Powders with a Space Holder Powder." MRS Advances 2, no. 26 (2017): 1387–92. http://dx.doi.org/10.1557/adv.2017.123.

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ABSTRACTIn the present study, we have attempted to produce the porous Ti–Al intermetallic based alloys by pressure-sintering of the elemental powders of Ti and Al through a combustion reaction, with a NaCl space holder to achieve the development of a highly porous structure. The powders of Ti (particle size: <45 μm) and Al (particle size: <45 μm) were mixed to various total compositions of Ti–0-40 Al (at.%), and NaCl (particle size: 300-400 μm) was mixed with the Ti/Al powder to give a highly porous structure. The mixed powder was sintered at 700 oC under a constant pressure of 30 MPa to form cylindrical specimens with a diameter of 20 mm. The soaking of the specimens in pure water allows for the removal of NaCl (with a volume fraction of 60 %) and the formation of the pores to achieve a controlled relative density of 0.4. The present process can produce porous Ti–Al alloys with various compositions. In as-sintered Ti–Al specimens, an inhomogeneous microstructure consisting of Ti particles surrounded by the a Ti–Al alloy layer (various Ti–Al intermetallic phases) was observed. The as-sintered specimens exhibited the brittle behavior under compression, which is independent of their Al content. However, in a Ti–20Al alloy heat-treated at 1300 °C, a nearly Ti3Al single-phase microstructure appeared in the porous specimen. The heat-treated porous Ti–20Al alloy shows both a high plateau-strength level of approximately 100 MPa and a high plateau-end strain over 50%, resulting in a high absorption energy. The present results demonstrate that controlling the microstructure for the formation of the Ti3Al single-phase would be an effective method to achieve high energy absorption capacity of the porous Ti–Al alloy.

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Lario, Joan, Ángel Vicente, and Vicente Amigó. "Evolution of the Microstructure and Mechanical Properties of a Ti35Nb2Sn Alloy Post-Processed by Hot Isostatic Pressing for Biomedical Applications." Metals 11, no. 7 (June 25, 2021): 1027. http://dx.doi.org/10.3390/met11071027.

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The HIP post-processing step is required for developing next generation of advanced powder metallurgy titanium alloys for orthopedic and dental applications. The influence of the hot isostatic pressing (HIP) post-processing step on structural and phase changes, porosity healing, and mechanical strength in a powder metallurgy Ti35Nb2Sn alloy was studied. Powders were pressed at room temperature at 750 MPa, and then sintered at 1350 °C in a vacuum for 3 h. The standard HIP process at 1200 °C and 150 MPa for 3 h was performed to study its effect on a Ti35Nb2Sn powder metallurgy alloy. The influence of the HIP process and cold rate on the density, microstructure, quantity of interstitial elements, mechanical strength, and Young’s modulus was investigated. HIP post-processing for 2 h at 1200 °C and 150 MPa led to greater porosity reduction and a marked retention of the β phase at room temperature. The slow cooling rate during the HIP process affected phase stability, with a large amount of α”-phase precipitate, which decreased the titanium alloy’s yield strength.

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Wang, Ge, Chun Zhang, Yu Ying Zhu, Zhi Gang Chao, and Qiang Li. "Mechanical Alloying for Preparation of Ti₅₀Fe₄₅Sn₅ Amorphous Alloys Powder." Key Engineering Materials 480-481 (June 2011): 104–8. http://dx.doi.org/10.4028/www.scientific.net/kem.480-481.104.

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Ti50Fe45Sn5 amorphous alloys powder was prepared by mechanical alloying (MA) in a high-energy planetary ball mill. The non-crystallization degree was tested by X-ray diffraction (XRD). It was shown from the XRD results that a higher ball to powder weight ratio (BPR) is advantageous in preparing amorphous alloys powder. The microstructure and shape of the powder was observed by scanning electron microscope (SEM). It was shown from the SEM results that the as-milled amorphous alloys powder is flake shape and assembles together to be agglomeration structure, which is a typical morphology of amorphous powders prepared by MA. Thermodynamic properties and crystallization kinetics behavior of the as-milled amorphous alloys powder were measured by differential scanning calorimeter (DSC). The supercooled liquid region △Tx is broad (up to 119K) and the reduction glass transforming temperature Trg (0.78) is great, which shows that the as-milled amorphous alloys powder has a strong glass-forming ability and the thermal stability of the powder is excellent.

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Nachtrab, W. T., P. R. Roberts, and H. A. Newborn. "Powder Metallurgy of Advanced Titanium Alloys." Key Engineering Materials 77-78 (January 1992): 115–40. http://dx.doi.org/10.4028/www.scientific.net/kem.77-78.115.

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Kobernik, N. V., R. S. Mikheev, and S. S. Kremlev. "Plasma-powder deposition of Babbit alloys." Welding International 29, no. 8 (December 22, 2014): 654–56. http://dx.doi.org/10.1080/09507116.2014.960702.

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Skachkov, O. A. "Heat-resistant structural-grade powder alloys." Metallurgist 48, no. 9-10 (September 2004): 484–86. http://dx.doi.org/10.1007/s11015-005-0010-5.

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Matsumoto, H., Y. Kajiura, M. Hosono, A. Hasegawa, H. Kumaoka, K. Yoshidome, and S. Mori. "Development of novel Fe based nanocrystalline FeBNbPSi alloy powder with high B_s of 1.41T by forming stable single amorphous precursor." AIP Advances 12, no. 3 (March 1, 2022): 035312. http://dx.doi.org/10.1063/9.0000259.

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The possibility of the powderization of precursor with a single amorphous phase was investigated in FeBNbP nanocrystalline alloy particles and FeBNbPSi nanocrystalline alloy powders. Fe90−xBxNb7P3 (x=9, 10), Fe79.5B9.5Nb7P3Si1 and Fe82−x B9Nb6P3Six (x=2, 3) powders were prepared by the gas atomization method using high pressure water for rapid quenching. The as-atomized particle as a precursor exhibiting low H c of 141 A/m with a single amorphous phase was observed from a cross sectional image and SAED pattern in the Fe80B10Nb7P3 nanocrystalline alloy powder. In addition, the stability of amorphous phase in the FeBNbP nanocrystalline alloy was also significantly improved by the addition of Si. Therefore, the as-atomized Fe79B9Nb6P3Si3 nanocrystalline alloy powder with Si as a precursor powder of nanocrystalline alloy was achieved to exhibit excellent magnetic softness of low H c of 53 A/m compared to the ordinary Fe73Si11B11Cr3C2 amorphous and Fe73.5Si13.5B9Nb3Cu1 nanocrystalline alloy powders. In addition, the Fe79B9Nb6P3Si3 powder after nanocrystallization at 873K achieved both high B s of 1.41T and low H c of 37 A/m compared to ordinary amorphous, and nanocrystalline alloys.

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Henriques, V. A. R., A. C. S. M. Dutra, and C. A. A. Cairo. "Production of Aerospace Tial Intermetallics for High Temperature Applications by Powder Metallurgy." Materials Science Forum 727-728 (August 2012): 44–49. http://dx.doi.org/10.4028/www.scientific.net/msf.727-728.44.

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During the recent years, alloys based on the intermetallic compound TiAl have attracted a considerable interest as potential competitors to steels and superalloys. Gamma-TiAl alloys are potential replacements for nickel and conventional titanium alloys in hot sections of turbine engines, as well as in orbital platform vehicles. The alloy design and efficient routes of TiAl processing are important technological challenges. Powder metallurgy is a near net shape process that allows the parts production with complex geometry at low costs. In this work, samples of Ti-48Al-2Cr-2Nb (at.%) were prepared from elemental and pre-alloyed powders mixed for 2 h, followed by cold uniaxial and isostatic pressing and sintered between 800 up to 1400°C, for 1 h, under vacuum. After metallographic preparation, sintered samples were characterized by SEM (Scanning Electron Microscopy), density analyses and Vickers microhardness measurements. The results indicated the viability of the pre-alloyed route and the tendency of a full lamellar microstructure of alternating gamma and α2 phases in high sintering temperatures.

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Liu, Binglin, Maosong Wang, Yulei Du, and Jingxiao Li. "Size-Dependent Structural Properties of a High-Nb TiAl Alloy Powder." Materials 13, no. 1 (January 1, 2020): 161. http://dx.doi.org/10.3390/ma13010161.

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TiAl-based alloys are promising light weight structural materials for high temperature applications in the field of aerospace. Recently, fabrication technologies starting from powders including powder metallurgy and additive manufacturing have been developed to overcome the difficulties in the processing, machining and shaping of TiAl-based alloys. Spherical alloy powders with different particle size distributions are usually used in these fabrication techniques. The purpose of this study is to reveal the size-dependent structural properties of a high-Nb TiAl powder for these fabrication technologies starting from powders. A high-Nb TiAl pre-alloyed powder with nominal composition of Ti-48Al-2Cr-8Nb (at. %) was prepared by the electrode induction melting gas atomization (EIGA) method. The phase structure and morphology of the as-atomized powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The size-dependent structural changes of the as-atomized powders with different sizes were studied by differential scanning calorimetry (DSC) and in situ high temperature XRD. It was found that with decreasing the powder size, the content of the γ-TiAl phase decreases and the α2-Ti3Al phase increases. The α2-Ti3Al to γ-TiAl phase transformation was found in the temperature range of 600–770 °C. Based on the present work, the structural characteristics of TiAl powders are strongly dependent on their particle size, which should be considered in optimizing the process parameters of TiAl alloys fabricated from powders.

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Huang, Guang Sheng, Ling Yun Wang, Zhong Wei Zhang, Guang Jie Huang, and Fu Sheng Pan. "Manufacturing Technique of Magnesium Alloy Sheets by Powder Rolling." Materials Science Forum 488-489 (July 2005): 445–48. http://dx.doi.org/10.4028/www.scientific.net/msf.488-489.445.

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Conventional manufacturing processes of metal and alloys sheets are rolling. The poor formability of magnesium alloys at room temperature makes rolling difficult. In the present paper, a manufacturing technique of sheets by powder rolling was employed to fabricate magnesium alloy sheets. The technique consisted of roll compaction, sintering, re-rolling and annealing. Powders of Mg-3 wt% Al mixed using a global mill were roll compacted into green sheets using two counter rotating rolls to the thickness of approximately 0.60 mm. Roll compacted green sheets were sintered at 823 K in argon atmosphere. Sintered green sheets were then re-rolled at ambient temperature to approximately 0.22 mm to obtain fully dense sheets. There was no significant edge cracking observed in the process of cold rolling. It is reasonable to believe that powder rolling is a promising technique for manufacturing magnesium alloys sheets.

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Bobkova, T. I., A. N. Beliakov, D. A. Gerashchenkov, E. Yu Gerashchenkova, A. F. Vasiliev, and B. V. Farmakovsky. "Powdered composites of Al–Zn–Sn alloys for functional coatings." Voprosy Materialovedeniya, no. 1(97) (August 10, 2019): 79–84. http://dx.doi.org/10.22349/1994-6716-2019-97-1-79-84.

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The features of the process of obtaining a powder composition from an alloy based on the Al–Zn– Sn system are studied. A technology has been developed for obtaining powders of optimal composition, including Al; 6–11% Zn; 6–11% Sn; 2–4% Si; 0.6–0.8% Ce. Functional wear-resistant coatings recommended for practical use in products of precision and power engineering were made by supersonic cold gas dynamic spraying.

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Journal articles on the topic 'Powder alloys'

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