The MIM industry is currently focusing on parts that are used in automobiles and medical instruments. Many of the parts in these categories are very small and often not easy to machine because of its complex geometry. Therefore MIM is well suited for the production of these parts. We tested the sinterability of SUS316L ultra fine powders (3,4, 6, 8micron) produced by ATMIX high-pressure water-atomization, and it showed excellent results. A density of 97% theoretical was obtained by sintering at 1373K when using the ultra fine powder (3micron). Specifically, the finer the powder size, higher was the sintered density. The surface roughness and accuracy are also greatly improved with ATMIX ultra fine powder.

Ti-6Al-4V has low specific gravity, high corrosion resistance and superior mechanical properties but it is very difficult to control oxygen content in MIM process. It is necessary to use powders with coarse particle size to decrease oxygen content of powders, so feedstocks with poor fluidity and sintered bodies with lower density are obtained in such cases. Fine titanium hydride-dehydride powders were blended with atomized powders to accomplish higher fluidity and sintered density. Sintered bodies had higher sintered density and mechanical properties equivalent to those of wrought materials by controlling oxygen content less than 0.35mass%.

The present work studies the influence of high-energy milling (HEM) and sintering cycle of Ti and Al powders on the obtainment of TiAl. This study shows that HEM modifies the diffusion processes during the sintering stage. The samples were obtained by cold uniaxial and isostatic pressing, pre-sintered at different temperatures, and heated up to the sintering temperature. This study also shows the effect of powder additions processed by HEM on the sintering behavior of elemental Ti and Al powders.

Ultra-fine grained and dispersion-strengthened titanium materials (Ti-Si, Ti-C, Ti-Si-C) have been produced by high energy ball milling and spark plasma sintering (SPS). Silicon or/and carbon were milled together with the titanium powder to form nanometer-sized and homogeneously distributed titanium silicides or/and carbides as dispersoids, that should prevent grain coarsening during the SPS compaction and contribute to strengthening of the material. The microstructures and the mechanical properties showed that strength, hardness and wear resistance of the sintered materials have been significantly improved by the mechanisms of grain refinement and dispersion strengthening. The use of an organic fluid as carrier of the dispersoid forming elements caused a significant increase in ductility.

[ ] oxide layer on the surface of each W(tungsten) nanopowder produced by the electric explosion of wire(EEW) process were formed during the 1vol.% air passivation process. The oxide layer hindered sintering densification of compacts during SPS process. The oxide phase was reduced to the pure W phase during SPS. The W nanopowder's compacts treated by the hydrogen reduction showed high sintered density of 94.5%. after SPS process at .

This paper presents the densification and microstructure evolution of bilayer components made from 316L stainless steel and M2 High speed steel during co-sintering process. The sintering was carried out at temperatures ranging from in a reducing atmosphere. The addition of boron to 316L was examined in order to increase the densification rate and improve the sintering compatibility between the two layers. It was shown that the mismatch strain bettwen the two layers induces biaxial stresses during sintering, influencing the densification rate. The effect of boron addition was also found to be positive as it improves the bonding between the two layers.

Thermoelectric conversion efficiency of thermoelectric elements can be increased by using a structure combining n-type and p-type semiconductors. From the above point of view, attention was directed at ZnO as a candidate n-type semiconductor material and investigations were made. As the result, a dimensionless figure of merit ZT close to 0.28 (1073K) was obtained for specimens produced by the PCS (Pulse Current Sintering) method with addition of specified quantities of , CoO, and to ZnO. It was found that the interstitial in the ZnO restrains the grain growth and CoO acts onto the bond between grains. The influence of the inclusion of and CoO onto the sintering behavior also was investigated.

We report on the mechanical and structural properties of nanocrystalline 8% and 10% mol yttria stabilized zirconia (YSZ) obtained using mechanical alloying (MA). The as-milled powders show a body-centered cubic structure with grain sizes in the nanometer scale. After uniaxial pressing and sintering the compacts exhibit good mechanical properties. We discuss the correlation of these enhanced properties with the microstructural changes induced by heat treatment.

In this study, the diffusion behaviors of C and Co in liquid phase sintering of WC-Co system were investigated whether these two components diffused in the same direction in case of having opposite gradient each other with not being phase. The green compacts with controlled compositions in not being of phase and gradient composition which one is WC-5Co-1.2%C, the other is WC-XCo-0.2%C (where X = 5, 10, 15, 20, 25) were sintered at and and then the diffusion behaviors of C and Co were investigated by analyses of compositional change, also determined for microstructure and microhardness. Also, same testing was carried out on the specimens with dual layers sintered in upright and reverse positions to evaluate the effect of gravity on the diffusion in liquid Co. From the results of this study, we can find the fact that the direction of diffusion for C and Co in WC-Co system during liquid phase sintering was different and the effect of gravity for the liquid was insignificant. Also other physical properties were changed on the diffusion of elements.

In this paper, we show some experimental results of binder-free WC sintered by Pulsed Electric Current Sintering (PECS) also known as Field Assisted Sintering Technology (FAST). These binder-free WC have extremely hardness and stiffness. However, these mechanical properties are dependent on the sintering condition, e.g., maximum temperature, applied pressure, etc. We show some relationship between mechanical properties and sintering condition to improve to sinter the binder-free WC.

Due to the increasing use that the stainless steel is getting recently in the nuclear industry, this document proposes the study of the stainless steel 316L with boron addition. With the final product, the properties of the stainless steel 316L (good mechanical properties and high corrosion resistance) with the boron neutron absorption properties are claimed to unify. The P/M technologies allow adding higher boron quantities than with the solidification conventional technologies, where segregation is produced.

The effect of chemical composition of the sintering atmosphere on density, microstructure and mechanical properties of Fe-3%Mn-(Cr)-(Mo)-0.3%C steels is described. Pre-alloyed Astaloy CrM and CrL, ferromanganese and graphite were used as the starting powders. Following pressing in a rigid die, compacts were sintered at 1120 and in atmospheres having different ratio and furnace cooled to room temperature. It has been found that the atmosphere composition has negligible effect on the as-sintered properties of the investigated materials.

In all conventional sintered PM products, the pores present are of two types, primary and secondary. Primary pores forming during compaction and latter during sintering, due to penetration of formed liquid through the matrix grain boundary. Effect of carbon addition on diffusion of Cu in SH737-2Cu system was investigated. After compaction and transient liquid phase sintering at and , samples were characterized for densification, showing rise in sintering density and reduction in swelling on carbon addition. Quantitative microstructural characterization (shape factor and pore size) revealed bimodal distribution for 0% carbon, more rounded pores for 0.9% carbon and higher sintering temperature, and pore coarsening at higher sintering temperature.

The study examines hardness pattern of SH737-2Cu-.9C samples transient liquid phase sintered at different temperatures viz. , and , heat treated by various methods and then tempered at different temperatures. Sintered samples were characterized for density and densification parameter, and austenitized at , subsequently cooled by four different methods viz. annealing, normalizing, oil and brine quenching. Hardness pattern was found minimum for air cooled and maximum for brine quenched, and samples sintered at had relatively higher hardness. The O.Q and B.Q samples were then tempered at , , and . Hardness pattern typically showed secondary hardness taking place, with maximum around .

The present study investigates the behavior of the sintering and hardness of stainless steel samples reinforced with NbC and TaC. Matrixes of pure stainless steel were compacted with addition of up to 3% wt NbC or TaC in a cylindrical die of steel at 700 MPa and sintered in an electrical resistance furnace under argon atmosphere. The sintered samples were characterized by density and hardness measurement, optical microscopy and scanning electron microscopy (SEM). The preliminary results show that the size and distribution of carbides influence in the sintering and hardness of the sintered samples.