Showing papers in "Powder Metallurgy in 2019"
TL;DR: High-entropy alloys (HEAs) have attracted a great deal of interest over the last 14 years and one reason for this level of interest is related to these alloys breaking the alloying principles.
Abstract: High-entropy alloys (HEAs) have attracted a great deal of interest over the last 14 years. One reason for this level of interest is related to these alloys breaking the alloying principles ...
120 citations
TL;DR: Binder Jetting Metal Additive Manufacturing (BJ-MAM) is a powder bed-based additive manufacturing technology as discussed by the authors, which consists of the deposition of liquid binder drople.
Abstract: Binder Jetting Metal Additive Manufacturing (BJ-MAM), known also as metal 3D-printing, is a powder bed-based additive manufacturing technology. It consists of the deposition of liquid binder drople...
69 citations
TL;DR: In this paper, material extrusion additive manufacturing (MEAM) is mainly used for the production of polymeric components, using feedstocks similar to those of powder injection molding, for the ceramic component.
Abstract: Material Extrusion Additive Manufacturing (MEAM) is mainly used for the production of polymeric components. Using feedstocks similar to those of powder injection moulding, MEAM of ceramic component...
23 citations
TL;DR: In this paper, the evolution of the electrical resistivity of metal powders during densification and the resulting current flow through punch, powder compact, and die was investigated, and the results showed that the electrical resistance of metal powder can change with densification.
Abstract: In this study, the evolution of the electrical resistivity of metal powders during densification and the resulting current flow through punch, powder compact, and die is investigated. The e...
22 citations
TL;DR: In this article, three 12CrNi2 alloy steels were successfully fabricated on 35CrMo alloy steel by laser melting deposition with the aim of investigating the effect of powder oxygen content on formability of the steels.
Abstract: Three various 12CrNi2 alloy steels were successfully fabricated on 35CrMo alloy steel by laser melting deposition with the aim of investigating the effect of powder oxygen content on formability of...
17 citations
TL;DR: In this article, the authors deal with Directed Energy Deposition (DED) that is a process in which the material is delivered directly into the melt pool and several kinds of nozzle have been developed and used.
Abstract: This work deals with Directed Energy Deposition (DED) that is a process in which the material is delivered directly into the melt pool. Several kinds of nozzle have been developed and used ...
17 citations
TL;DR: AlCrFeCoC high entropy alloy was synthesized through mechanical alloying and spark plasma sintering as mentioned in this paper, and the milling time had a strong influence on the particles shape and structure.
Abstract: AlCrFeCoC high entropy alloy was synthesised through mechanical alloying and spark plasma sintering. The milling time had a strong influence on the particles shape and structure and consequently on...
16 citations
TL;DR: In this article, the authors proposed a promising alternative as an implant material due to their good properties and low Young's modulus, compared to other Ti-alloys currently employed as biomaterials.
Abstract: Ti–Nb β alloys are a promising alternative as an implant material due to their good properties and low Young’s modulus, compared to other Ti-alloys currently employed as biomaterials. In this study...
14 citations
TL;DR: In this paper, the preparation of alloys based on intermetallic compounds in the Ti-Al-Si system by powder metallurgy using mechanical alloying and the spark plasma sintering (SPS) method is described.
Abstract: This work is devoted to the preparation of alloys based on intermetallic compounds in the Ti–Al–Si system by powder metallurgy using mechanical alloying and the spark plasma sintering (SPS) method....
11 citations
TL;DR: AISI 316L powder mix was sieved in three particle sizes and successively compacted on rings with two different H/(Dext-Dint) ratios as discussed by the authors.
Abstract: AISI 316L powder mix was sieved in three particle sizes and successively compacted on rings with two different H/(Dext-Dint) ratios. The height and diameters were measured by a CMM at the green and...
11 citations
TL;DR: The equiatomic ratio CrMnFeCoNi high entropy alloy (HEA) was prepared by mechanical alloying (MA) and spark plasma sintering in this article.
Abstract: The equiatomic ratio CrMnFeCoNi high entropy alloy (HEA) was prepared by mechanical alloying (MA) and spark plasma sintering. This paper reports the behaviour of MA, the phase formation, microstruc...
TL;DR: In this paper, the effect of HIPPT on the densification, microstructure and mechanical properties of HIPed powder compacts were investigated, and the relative density showed a regional increase after HIPPT.
Abstract: Hot isostatic pressing (HIP) is an ideal fabrication technique for products with complex structure, but also a reliable post-treatment method. The individual effect of the HIP or HIP post-treatment (HIPPT) on the mechanical properties of powder compacts have been investigated, but little attention has been paid to their combined effect. In this study, the effect of HIPPT on the densification, microstructure and mechanical properties of HIPed powder compacts were investigated. The relative density shows a regional increase after HIPPT. The interlayer spacing of lamellar α phase is increased, equiaxial grains are coarsened and high-angle grains are decreased. Moreover, an obvious increase in elongation is detected, which demonstrates that HIPPT is beneficial to improve the properties of HIPed powder compacts.
TL;DR: In this article, a 15Cr13MoY alloy steel powder used for direct laser deposition was produced using the vacuum induction gas atomisation (VIGA) method, and the characteristics and laser printability of the powder were described.
Abstract: A novel 15Cr13MoY alloy steel powder used for direct laser deposition was produced using the vacuum induction gas atomisation (VIGA) method. The characteristics and laser printability of th...
TL;DR: In this paper, the effects of Cu particle size on diamond composites experimentally were investigated and the hybrid microwave sintering process was proposed to obtain the particle size microstructure.
Abstract: The paper investigates the effects of Cu particle size on diamond composites experimentally. The hybrid microwave sintering process is proposed to obtain the particle size microstructure th...
TL;DR: The binders used in this article were of two types: binder I, comprising high-density polyethylene, paraffin wax and stearic acid as well as binder II, composing high density polyethylenes, pol...
Abstract: The binders used in this work were of two types: binder I, comprising high-density polyethylene, paraffin wax and stearic acid as well as binder II, composing high-density polyethylene, pol...
TL;DR: In this paper, a new shrinkage kinetic equation accounting for the extension of the interparticle contact areas is proposed, and the mass transport mechanism responsible for shrinkage is bulk diffusivity.
Abstract: A new shrinkage kinetic equation accounting for the extension of the interparticle contact areas is proposed. The mass transport mechanism responsible for shrinkage is bulk diffusivity. Shrinkage i...
TL;DR: A low-cost gas atomisation technology for additive manufacturing of spherical titanium powder was developed in this paper. But this technology is not suitable for the use of additive manufacturing in medical applications.
Abstract: A novel low-cost gas atomisation technology producing spherical titanium powder (wire induction heating gas atomisation, WIGA) has been developed for additive manufacturing. Combined with the gas a...
TL;DR: In this article, a hot-press sintering process was used for the preparation of alloys with composition of Ta-10 wt.% W and Ta- 10 w.% Al, respectively.
Abstract: Alloys with composition of Ta-10 wt.% W and Ta-10 wt.% W-6 wt.% Al, respectively, were prepared by the hot-press sintering process. The oxidation behaviour at 900°C and 1000°C was studied. ...
TL;DR: In this paper, the effect of sintering variables on the zinc loss during sinting of brass was investigated. But the effect was limited to the case of brass powder, and it was shown that zinc loss, evident through mass change, starts during heating of the powder at approximately 700°C.
Abstract: The effect of sintering variables on the zinc loss during sintering of brass was investigated. Zinc loss, evident through mass change, starts during heating of the powder at approximately 700°C. By...
TL;DR: In this article, a composite made of a porous stainless steel (SS) 316L substrate coated with Nb was investigated as a novel porous transport layer (PTL) for proton exchange membrane electrolysis.
Abstract: In this study, a composite made of a porous stainless steel (SS) 316L substrate coated with Nb was investigated as a novel porous transport layer (PTL) for proton exchange membrane electrolysis cel...
TL;DR: Twinning Induced Plasticity (TWIP) steels are high manganese austenitic steels that have caused growing interest over the last decade due to their unique combination of strength and elongation as mentioned in this paper.
Abstract: Twinning Induced Plasticity (TWIP) steels are high manganese austenitic steels that have caused growing interest over the last decade due to their unique combination of strength and elongation. Nev...
TL;DR: In this article, the pore formation process for a high-temperature porous Mo-Si-B alloy produced by in situ reaction synthesis from elemental starting powders was investigated systematically as a function of the sintering temperature.
Abstract: The pore formation process has been studied for a high-temperature porous Mo–Si–B alloy produced by in situ reaction synthesis from elemental starting powders. The expansions, phase transformations, microstructure and pore parameters were investigated systematically as a function of the sintering temperature. For sintering temperatures of 1200°C and above, a multiphase mixture of the oxidation-resistant intermetallic compounds Mo3Si, Mo5Si3 and Mo5SiB2 was obtained. It was found that the porous alloys exhibit uniform skeletons with fine grains, high porosities and centred pore size distributions. Characterisation data obtained from samples sintered at temperatures from 1200 to 1600°C are used to deduce the processes which occur at each stage in the reaction synthesis. This helps to explain the formation mechanism for the pores and skeletons in this novel material.
TL;DR: In this article, a multi-functional binder with adhesive and lubricant effect was designed, and the thixotropic properties of the binder components and the resulting binder, the adhesive effect and compaction b...
Abstract: A new multi-functional binder with adhesive and lubricant effect was designed, and the thixotropic properties of the binder components and the resulting binder, the adhesive effect and compaction b...
TL;DR: In this article, the electrochemical corrosion properties of high-energy milled Ti6Al4V alloy are investigated, which is produced by high energy milling at different milling times in different industrial settings.
Abstract: In this study, the electrochemical corrosion properties of high-energy milled Ti6Al4V alloy are investigated. The Ti6Al4V alloy is produced by high-energy milling at different milling times in mech...
TL;DR: In this paper, physical properties, microstructure, and mechanical properties of the MIM parts have been characterised to understand the evolution of strength during various steps in MIM processing.
Abstract: Metal injection moulding (MIM) is an established process for high volume production of complex shaped metallic parts using commercially available feedstocks. The characteristics of parts after moulding, debinding, and sintering cannot be simply predictable from raw materials because the properties get altered with the process parameters and the corresponding levels of porosity during processing steps. In this study, physical properties, microstructure, and mechanical properties of the MIM parts have been characterised to understand the evolution of strength during various steps in MIM processing. Feedstocks with different binder loading show a considerable difference in physical as well as mechanical characteristics. During sintering of parts which have solid loading of grinding sludge, simultaneous in situ reduction and densification takes place, whereas only densification occurs in carbonyl iron parts. It is, therefore, possible to make complex shaped parts of different levels of porosity from d...
TL;DR: In this paper, the authors examined the time-dependent evolution of the 3D morphology of micropores in sintered iron during the tensile test, and showed that the networked open pores grow wider than 20'µm along the direction, resulting in internal necking of the specimen.
Abstract: Synchrotron X-ray laminography was used to examine the time-dependent evolution of the three-dimensional (3D) morphology of micropores in sintered iron during the tensile test. 3D snapshots showed that the networked open pores grow wider than 20 µm along the tensile direction, resulting in the internal necking of the specimen. Subsequently, these pores initiated the cracks perpendicular to the tensile direction by coalescing with the surrounding pre-existing microvoids or with the secondary-generated voids immediately before fracture. Topological analysis of the barycentric positions of these microvoids showed that they form the two-dimensional networks within the ∼20 µm of radius area. These observations strongly indicate that the microvoid coalescence could occur on shear planes formed close to the enlarged open pores or between closed pores by strain accumulation and play an important role in the crack initiation.
TL;DR: In this article, the main material used in laser additive manufacturing (LAM) of aerospace engine turbine blades was prepared by the vacuum-inducable superalloy powder (VINP).
Abstract: Nickel-based K417G superalloy powder is the main material used in laser additive manufacturing (LAM) of aerospace engine turbine blades. In this study, K417G powder was prepared by the vacuum induc...
TL;DR: In this paper, the IN713C super alloy was applied to gasoline engine turbochargers which demand a high operating temperature over 950°C, and the results showed that the super alloy is suitable for turbocharging.
Abstract: To find a proper super alloy applied to gasoline engine turbochargers which demand a high operating temperature over 950°C, the IN713C super alloy was investigated in this study. The rheolo...
TL;DR: In this article, the Fe-2Cu-0.8C powder mixes were prepared by a wet mixing and spray-drying process using iron, copper, graphite and zinc stearate as main raw materials, and stearic acid, alcohol wax and amide wax as...
Abstract: Fe-2Cu-0.8C powder mixes were prepared by a wet mixing and spray-drying process using iron, copper, graphite and zinc stearate as main raw materials, and stearic acid, alcohol wax and amide wax as ...
TL;DR: Among refractory metals, tantalum has long been the primary material of use in high strain rate applications as mentioned in this paper, and hot pressing is a technique to produce specimens with high density and homogeneous properties.
Abstract: Among refractory metals, tantalum has long been the primary material of use in high strain rate applications. Hot pressing (HP) is a technique to produce specimens with high density and homogeneous...