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Showing papers on "Powder metallurgy published in 2021"


Journal ArticleDOI
TL;DR: In this paper, a detailed review of the physical processes during 3D printing and the fundamental science of densification after sintering and post-heat treatment steps are provided to understand the microstructural evolution and properties of binder jetted parts.

293 citations


Journal ArticleDOI
TL;DR: In this paper, the precipitation mechanisms of O phase, phase transformation and microstructure control of Ti2AlNb-based alloys are reviewed, and the phase diagram as well as coarsening behavior of these alloys in ageing process is also reviewed.

73 citations


Journal ArticleDOI
TL;DR: In this article, powder metallurgy with space holder (SH) is a powerful technology used to produce porous Ti structures, it is discussed its potential for the fabrication of medical devices from the perspectives of both design and manufacture.

60 citations


Journal ArticleDOI
TL;DR: In this paper, a comprehensive review of effective parameters on the microstructure and final properties of NiTi manufactured parts through PM methods is provided, whereas the effect of alloying elements on the properties is discussed.

60 citations


Journal ArticleDOI
TL;DR: In this paper, the fabrication of the AA7075/B4C micro composite subjected to different sintering techniques was investigated, and the results showed that conventional sintered composite showed inadequate mechanical responses because of their high-temperature processing and time, intermetallic compound formation, high porosity levels, and high strain to fracture values.

50 citations


Journal ArticleDOI
01 Jan 2021-Vacuum
TL;DR: In this paper, high entropy alloy alloys (HEA), produced by powder metallurgy, were subjected to boriding to improve their mechanical properties, such as hardness, fracture toughness and nanoindentation responses.

44 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of yttria dispersion and interfacial bonding by ball milling technique on the performance of a 0.5-wt% Yttria nanoparticle reinforced 7075 aluminum alloy composite were examined.

44 citations


Journal ArticleDOI
01 May 2021-Vacuum
TL;DR: In this article, the effects of the additive on the microstructure, hardness, wear, and high-temperature oxidation behavior of high entropy alloys were investigated, and the best wear resistance and the lowest friction coefficient were seen in the AlCrFeNiSi alloy.

42 citations


Journal ArticleDOI
TL;DR: In this article, a powder-metallurgy-based fabrication route was proposed to achieve a high synergy of tensile strength and ductility through cold-consolidation of CoCrFeMnNi high-entropy alloy powder using high-pressure torsion followed by annealing.

42 citations


Journal ArticleDOI
TL;DR: In this article, an aluminium-based metal matrix composite material was developed via powder metallurgy considering various input process parameters, such as sintering time, sinter temperature, and compactness.
Abstract: In this work, an aluminium-based metal matrix composite material was developed via powder metallurgy considering various input process parameters. Sintering time, sintering temperature, and compact...

36 citations


Journal ArticleDOI
TL;DR: In this paper, a re-investigation has been done on the effect of the powder metallurgy process parameters on the physical and mechanical properties of Aluminium matrix composites.

Journal ArticleDOI
TL;DR: Inspired by nacre's design principle, a bottom-up strategy by self-assembly alignment of flake powders, namely flake powder metallurgy, is employed to fabricate bio-inspired laminated composites with brick-and-mortar structure as mentioned in this paper.
Abstract: Inspired by nacre’s design principle, a bottom-up strategy by self-assembly alignment of flake powders, namely flake powder metallurgy, is employed to fabricate bioinspired laminated composites with brick-and-mortar structure. The microscale flake Al2O3 powders and flake Al powders with native Al2O3 nanolayers are utilized to fabricate the bioinspired hierarchical Al2O3/Al laminated composites, and the composites with 5 vol% Al2O3 achieves an enhancement of 22% in strength with only a 7% compromise on ductility, leading to a notable improvement in toughness (17%) compared to the corresponding Al matrix. The higher strain hardening due to enhanced dislocation accumulation capacity at hierarchical Al2O3/Al interface can delay the occurrence of necking, and the large elongation after peak stress is attributed to multiple extrinsic toughening effect from brick-and-mortar structure. The bottom-up strategy can guide the design and fabrication of advanced bioinspired laminated composites to achieve enhanced mechanical performance.

Journal ArticleDOI
01 Apr 2021-Silicon
TL;DR: In this paper, Ni-Co-Cr-SiC composites with various weight percentages were manufactured via powder metallurgy (PM) route and the powders were mixed using planetary ball mill for a period of 10h.
Abstract: In this investigation, Ni-Co-Cr-SiC composites with various weight percentages were manufactured via powder metallurgy (PM) route. The compositions of the composites are Ni-10%Co-5%Cr, Ni-10% Co-5%Cr-4%SiC, Ni-10%Co-5%Cr-8%SiC and Ni-10%Co-5%Cr-12%SiC. The powders were mixed using planetary ball mill for a period of 10 h. The ball milled powders were subjected to X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) analysis. By utilizing 150 kN hydraulic press with appropriate punch and die the ball milled powders were compacted as a cylindrical billets. The green compacts were sintered in a tubular furnace at two different temperatures 1000 °C and 1200 °C for3 h. The characterization examination namely XRD, SEM and Energy Dispersive Analysis (EDAX) was made on the sintered samples. Unreinforced Ni-Co-Cr exhibits higher sinterability at both sintering temperature. The sintering temperature and reinforcement weight percentage effect on the mechanical properties and corrosion behavior of the composites were examined. From these investigations, the mechanical properties and corrosion resistance of the composites were enhanced while increasing the sintering temperature and SiC weight percentage in the Ni-Co-Cr super alloy matrix.

Journal ArticleDOI
TL;DR: In this article, the authors synthesized Cu modified Ti-6Al-4-V (TC4) powders with various Cu contents (0, 1, 3, 5, 10, 10), which were further strengthened with 0.3% graphene oxide nanosheets (GONs) using a powder metallurgy technology.

Journal ArticleDOI
TL;DR: In this paper, the recent progress on fabrication techniques, microstructure and property regulation that ensure high-performance Tungsten-copper composites/pseudo alloys with excellent properties are reviewed, along with various chemical methods for nano-powder synthesis.
Abstract: Tungsten‑copper (W Cu) composites/pseudo alloys with excellent properties are extremely desirable for applications as electrode materials, functional graded materials, electronic packaging materials, electrical contacts, as well as other aerospace and military candidates. This paper reviewed the recent progress on fabrication techniques, microstructure and property regulation that ensure high-performance W Cu alloys. Besides the well-developed traditional powder metallurgy including the parameter modification, powder pre-treatment and severe plastic deformation post-treatment, extensive novel sintering or manufacturing techniques including microwave sintering, spark plasma sintering, field-assisted sintering and additive manufacturing of W Cu alloys are reviewed, along with various chemical methods for nano-powder synthesis. Subsequently, the microstructure and property regulation by pure metal elements and introduction of second phases with great details are provided. Based on the review with all-sided perspectives for W Cu alloys, future developments and potential research challenges for W Cu alloys are summarized and proposed finally.

Journal ArticleDOI
TL;DR: In this article, a detailed discussion was made about the surface modification carried out on the materials during the EDM process and the influence of powder particles present in the dielectric fluid on minimizing the formation of recast layer and crater formation was discussed.

Journal ArticleDOI
01 Feb 2021-Vacuum
TL;DR: In this paper, the impact of wear test input parameters on the wear rate is identified and the optimized parameter to attain low wear rate was determined through Taguchi and ANOVA analysis by using L16 orthogonal array.

Journal ArticleDOI
TL;DR: A series of low-cost Ti-10Mo-xFe alloys were fabricated using conventional press and sinter powder metallurgy to investigate the effect of Fe content on their phase stability, sintering response, microstructure and mechanical properties as discussed by the authors.

Journal ArticleDOI
Zhengyan Zhou1, Bin Liu1, Wenmin Guo1, Ao Fu1, Heng Duan1, Weihua Li1 
TL;DR: In this paper, the corrosion behavior and mechanism of a novel FeCrNi medium entropy alloy (MEA) prepared by powder metallurgy method in 3.5% NaCl solution was investigated.

Journal ArticleDOI
TL;DR: In this paper, the impact of molybdenum (Mo) inclusion on microstructure, mechanical, and machinability behavior of steels manufactured with powder metallurgy (PM) approach was presented.
Abstract: This study presents the impact of molybdenum (Mo) inclusion on microstructure, mechanical, and machinability behavior of steels manufactured with powder metallurgy (PM) approach. PM steel samples with different molybdenum ratios were pressed at 750-MPa pressing pressure and sintered in the atmosphere-controlled tube furnace at 1400°C for 1 h. While particle size and distribution of phases of PM steels with different molybdenum ratios were determined by optical microscope, mechanical properties were determined by applying tensile test. The results were observed that 3% Mo weight-added steel displayed the maximum yield and tensile strength. In addition, the machinability properties of 3% Mo-added steel, which has the highest yield and tensile strength, were investigated. In this work, we researched the thrust force and surface roughness as machinability output, and drilling parameters on the output were determined by utilizing analysis of variance. Finally, SEM images were taken from the inner surfaces of the machined holes and the fractured surfaces from tensile test, and information about the machinability of this alloy produced with PM was presented. As a result, an increase in yield and tensile strength and a reduction in strain were identified with the increase in Mo content. Moreover, the coated cutting tools are better on the machining output than the uncoated cutting tools in terms of green environment. The most important factors on the Fz and Ra are the coating condition and the feed rate with 56.53% and 43.62% PCR, respectively.

Journal ArticleDOI
TL;DR: In this article, the effect of milling time (15, 30, 45, and 60h) and spark plasma sintering (SPS) conditions on microstructure, hardness, and density of lightweight high entropy alloy (LWHEA) were studied.
Abstract: In this study, we synthesized a new Al16.6Cu16.6Fe16.6Mn16.6Mg16.6Ti16.6 lightweight high entropy alloy (LWHEA) by high energy ball milling and spark plasma sintering (SPS). The effect of milling time (15, 30, 45, and 60 h) and SPS conditions (600 and 700 °C) on microstructure, hardness, and density of LWHEAs were studied. The results showed that milled LWHEA is base centered cubic (BCC) structured, consisting of dual BCC1/BCC2 matrix with dispersed minor Cu2Mg precipitates and Ti. After SPS of milled samples, the BCC2 phase fraction was increased gradually. The distribution of Ti was uniform up to 45 h milled sample SPSed at 600 °C. However, porosity was built up beyond 45 h milling and higher SPS temperature (700 °C). The presence of finer secondary phases in the HEA matrix contributes to the dispersion hardening. The optimum microhardness and density of LWHEA AlCuFeMnMgTi were around 770 HV and 4.34 g cm− 3 which is superior to other conventional alloys such as Al or Ti-based alloys.

Journal ArticleDOI
TL;DR: In this paper, the hardness and surface roughness of the NiTip/AA6061 metal matrix composites (MMCs) have been tested and compared with the results available in the published source to assess the novelty of the present investigation.

Journal ArticleDOI
TL;DR: In this paper, iron-and copper-based PM pads were used to mating with the C/C-SiC brake disc for high-speed trains, and the coefficient of friction of the carbon/ceramic disc-PM brake pair varied nearly between 0.35 and 0.6 under different braking conditions.

Journal ArticleDOI
TL;DR: In this paper, a microstructure-based model using microscopically non-uniform dispersion of CNTs was proposed to account for the mechanical properties with better prediction than the traditional models.
Abstract: Aluminum composites reinforced with carbon-based nano-particles or fibers have been widely studied. Yet, the rate dependence of their properties has been barely reported. In the present study, CNTs-reinforced Al composites with CNTs of two aspect ratios were produced by different powder metallurgy methods, followed by spark plasma sintering and hot extrusion. The mechanical properties and the underlying mechanisms of CNTs-reinforced Al composites at various loading rates were studied, with the aim of exploring the role of CNTs on strengthening, esp. on rate-dependent properties. The mechanical experiments revealed that the addition of CNTs not only increased the strength but also the strain rate sensitivity in comparison with pure Al. It was found that, under dynamic loading, the materials showed an increased strength and elongation-to-failure simultaneously, due to improved strain hardening rates. A careful analysis suggested that the long-range back stress produced at the CNTs-Al interfaces and the geometrically necessary dislocations accumulated due to strain gradient along the interface, mainly contributed to the strain hardening of CNTs/Al composites. A novel microstructure-based model using microscopically non-uniform dispersion of CNTs was proposed to account for the mechanical properties with better prediction than the traditional models. The results might shed some light on understanding metal matrix composites reinforced with nano-particles or fibers.

Journal ArticleDOI
TL;DR: In this article, two different sintering techniques, namely conventional and microwave, were implemented to determine the effect on microstructural and mechanical properties, including tensile, compression, and hardness, with the help of UTM and Vickers microhardness machine.

Journal ArticleDOI
TL;DR: In this paper, the authors focus on fabrication of AA7075/B4C/Graphite hybrid composite by varying the compaction pressures while cold compaction process, results reveal that increased compaction pressure has very positive impact on mechanical properties of the composite material.

Journal ArticleDOI
TL;DR: In this paper, pre-mixed pure Ti powder and ZrH2 particles were employed to prepare extruded Ti-Zr alloys with a low hydrogen content via dehydrogenation after sintering.

Journal ArticleDOI
TL;DR: In this article, a bimodal carbon nanotube reinforced 2009Al (CNT/2009Al) composites were fabricated by powder metallurgy followed with extrusion.
Abstract: Bimodal carbon nanotube reinforced 2009Al (CNT/2009Al) composites were fabricated by powder metallurgy followed with extrusion. It indicated that the width, length and grain size in the coarse grain (CG) bands increased with the increase of the extrusion temperature, while no obvious grain size change was observed in the ultra-fine grain zones. The bimodal composite showed a double yield phenomenon. The first yield strength which resulted from the yielding of the CG, was similar for all composites extruded with different temperatures. The second yield strength decreased, but the ultimate tensile strength retained stable and the elongation increased with increasing the extrusion temperature. The composite extruded at 470 °C exhibited a 76% ductility increase with nearly no ultimate tensile strength loss as compared to one extruded at 370 °C. The better stress relaxation ability of large-sized grains in the CG bands was believed to be the reason for the good strength-ductility.

Journal ArticleDOI
TL;DR: In this article, the influence of heat treatment and hot working process on the precipitation behavior of silicide, as well as on the effect of Si on the properties and strengthening mechanism of high temperature titanium alloys.
Abstract: Silicon (Si), which exists in the form of solid solution and silicide, is an important component in high temperature titanium (Ti) alloys. The content of Si is often limited to less than 0.5wt.%, but powder metallurgy shows the potential for the preparation of titanium alloys with high Si content and high temperature. The addition of Si is beneficial to the improvement of strength, creep resistance and oxidation resistance of high temperature titanium alloy, but it will reduce the plasticity, especially the plasticity at room temperature. In this review, with particular stress on the influence of heat treatment and hot working process on the precipitation behavior of silicide, as well as on the effect of Si on the properties and strengthening mechanism of high temperature titanium alloys. The development direction of high temperature titanium alloy containing Si is to increase the content of Si and to control the precipitation behavior of silicide through reasonable process.

Journal ArticleDOI
TL;DR: In this paper, the precipitates in Ti-Ag alloy made an important contribution to antibacterial activity, and the antibacterial effects, expression of reactive oxygen species (ROS), protein leakage and biocompatibility were investigated by plate count method, staining technology and cell test.