Effects of Chromium Addition on Preparation and Properties of Bulk Cementite  

作　　者：Bao-chao ZHENG Zhi-fu HUANG Jian-dong XING Yi-yang XIAO Xiao FAN Yong WANG 

机构地区：[1]State Key Laboratory for Mechanical Behavior of Materials,School of Materials Science and Engineering,Xi'an Jiaotong University

出　　处：《Journal of Iron and Steel Research International》2016年第8期842-850,共9页

基　　金：Item Sponsored by National Natural Science Foundation of China(51371138)

摘　　要：Bulk cementites with the Cr contents of 0,3.01,6.03,8.22,and 11.51mass% were prepared by mechanical alloying（MA）and spark plasma sintering（SPS）.The results indicated that when the Cr content was low（3.01mass%）,the phases were composed of cementite with a small amount ofα-Fe at a sintering temperature of 1 173 K,but the microstructure became single-phase alloyed cementite as the Cr content was further increased.It showed that microaddition of Cr was beneficial for promoting the formation of cementite.Furthermore,the mechanical performance of cementite can be greatly affected by the variation of Cr content.The hardness,elastic modulus and elastic recovery presented a remarkably increasing tendency with the addition of Cr,and the maximum micro-hardness and elastic modulus values reached 1 070.74 HV and 199.32 GPa,respectively,which were similar to the precipitation phase（cementite）obtained by melting and casting techniques.Moreover,when the Cr content was below 11.51mass%,the crystal structure of Fe3C-type cementite would not change with increasing the Cr content.A Cr atom replaced an Fe atom in the lattice of the cementite,and voids appeared when Cr was doped into the cementite at content of about11.51mass%,causing the relative density to decrease.Bulk cementites with the Cr contents of 0,3.01,6.03,8.22,and 11.51mass% were prepared by mechanical alloying（MA）and spark plasma sintering（SPS）.The results indicated that when the Cr content was low（3.01mass%）,the phases were composed of cementite with a small amount ofα-Fe at a sintering temperature of 1 173 K,but the microstructure became single-phase alloyed cementite as the Cr content was further increased.It showed that microaddition of Cr was beneficial for promoting the formation of cementite.Furthermore,the mechanical performance of cementite can be greatly affected by the variation of Cr content.The hardness,elastic modulus and elastic recovery presented a remarkably increasing tendency with the addition of Cr,and the maximum micro-hardness and elastic modulus values reached 1 070.74 HV and 199.32 GPa,respectively,which were similar to the precipitation phase（cementite）obtained by melting and casting techniques.Moreover,when the Cr content was below 11.51mass%,the crystal structure of Fe3C-type cementite would not change with increasing the Cr content.A Cr atom replaced an Fe atom in the lattice of the cementite,and voids appeared when Cr was doped into the cementite at content of about11.51mass%,causing the relative density to decrease.

关 键 词：modulus sintering spark hardness alloyed melting remarkably replaced alloying amorphous 

分 类 号：TF125.1[冶金工程—粉末冶金]