Development of iron-iron carbide composite by planetary milling and conventional sintering

Abstract

Fe-6.67 wt. %C and Fe-1 wt. %C powders were milled in a dual drive planetary mill for 40 h. It has been found that there is a formation of Fe3C and other iron carbides after 40 h of milling. However, the formation of iron carbide is more in the case of Fe-6.67 wt. %C as compared to Fe-1 wt. %C. The reduction in particle size is very fast up to 10 h of milling and after that it remains constant. It has been found that after 40 h of milling particle size is 10.47¥ìm and 10.59 ¥ìm for Fe-6.67 wt. %C and Fe-1 wt. %C respectively. It has been also found from SEM that the powder particles are flakey in nature at the initial milling period due to the ductile nature of iron but in later stages powder become brittle and breakage takes place. Maximum density was obtained 65.47 and 62.28 for Fe-6.67%C and Fe-1wt. %C sintered at 1250¨¬C for 1.5 h, similarly maximum Vickers hardness 836 and 780 are obtained for Fe-6.67 wt. %C and Fe-1 wt. %C sintered at 1250¨¬C for 1.5 h. From wear study it is established that wear depth is less for Fe-6.67 wt. %C as compared to Fe-1 wt. %C. It is also found that wear depth decreases with increase in sintering temperature and sintering time due to the higher density and hardness.