Sinterability studies of high carbon steel powders containing nickel, molybdenum, cobalt and manganese

Abstract: The automobile industry is a major consumer of powder metallurgy (PM) components. Occasionally, as in the current case of this investigation, new alloy compositions are specified for production of PM components and research is required to optimize production. This work was aimed at better understanding the influence of alloying additions on the sintering behaviour of the Fe-based powder mix containing high carbon content (up to 0.9 wt.%), and the alloying elements cobalt, molybdenum and nickel. Both the blended elemental and pre-alloyed powder mixtures were investigated whilst attempting to optimize the sintering conditions to achieve a higher density. Dilatometer, DSC with TGA were used to investigate the influence of alloying elements on the sintering behaviour of the Fe powder. Metallographic examination using optical microscopy along with scanning electron microscopy (SEM) combined with energy dispersive X-ray spectroscopy (EDS) has been performed in an attempt to relate the results obtained from dilatometer to the microstructure of the alloys. Response surface methodology (RSM) with central composite design (CCD) was also applied to study the influence of sintering parameters (sintering temperature, time and hydrogen content) with the aim of maximising the sintered density of the materials...M.Tech. (Engineering Metallurgy