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The iron-copper-carbon alloys are used extensively in powder metallurgy due to their superior dimensional control; however, they possess lower mechanical properties, corrosion resistance and wear resistance than their wrought counter part. In recent years, there have been concerted attempts to engineer ferrous alloys with high dimension tolerance and enhanced mechanical properties. One such approach is to use prealloyed iron powder instead of pure iron, mixed with copper and carbon. SH737-2Cu-C is one such alloy. The present study focuses on the effect of carbon addition on diffusion of Cu in SH737 alloys system via microstructural studies. SH737-2Cu alloys were compacted, sintered and characterized. The materials were characterized according to their density, densification parameter, shape factor, and pore size distribution. The microstructural studies revealed bimodal pore distribution in the sample with no carbon, due to the presence of primary and secondary porosity. The shape factor distribu tion showed more roundedness in the case of carbon added alloys. The size of the primary pores depends on compaction pressure and powder size distribution. On the other hand, size and morphology of the secondary pore strongly depends on Cu powder size, its homogeneity and sintering temperature. Also, an increase in the sintering temperature increased the roundedness and the pores became coarser.

The usage of powder metallurgy aluminium compacts in lieu of ferrous components in automotives helps to lower vehicle weight. The major drawback in the commercially available press sintered aluminium alloy is porosity which is mainly dependent on the powder metallurgical process parameters such as compaction pressure, sintering temperature and cooling rate after sintering. In this paper the effect of particle size and furnace controlled cooling after sintering on porosity level and micro hardness of an elemental 6061 aluminium alloy has been investigated. Aluminium particle sizes of 20 µm and 150 µm were used. The elemental 6061 aluminium alloy powders are warm compacted at 175 MPa. After sintering for about one hour at 600°C, the aluminium compacts were furnace cooled at the rate of 1°C /min to different temperatures of 500°C, 400°C, 300°C and 200?C. When the cooling temperature after sintering inside the furnace is effected at various temperatures from 600°C to 200°C, for a precipitate hardened aluminium compacts with aluminium particle size of 20 µm, the porosity level reduced by 26% and that for aluminium particle size of 150µm, the porosity level reduced by 23%. Marked improvement in micro hardness value is also observed correspondingly

The present study examines the change in hardness of sintered hardened steel (SH737-2Cu-0.9C) sintered at different temperatures, heat treated by various methods and then tempered at different temperatures. The samples were transient liquid phase sintered at 1120 °C, 1180 °C and 1250 °C respectively. The sintered samples were characterized then for density and densification parameter. The samples were austenitized at 900 °C and cooled by four different methods viz. furnace cooling (annealing), air cooling (normalizing), oil quenching, and brine quenching. The samples were then tested for their hardness using Vickers's hardness at 10 kgf load. The trend of hardness observed was found minimum for air cooled and maximum for brine quenched. In case of sample sintered at 1250 °C, relatively higher hardness was observed. The oil and brine quenched samples were then tempered at 200 °C, 400 °C, 600 °C and 700 °C. The hardness pattern observed typically showed secondary hardness taking place (due to presence of Mn and Mo) and reaching the maximum around 600 °C.