Effect of WC grain size on mechanical properties and microstructures of cemented carbide with medium entropy alloy Co-Ni-Fe binder  

WC晶粒尺寸对中熵合金(Co-Ni-Fe)粘结剂硬质合金力学性能和微观组织的影响

作　　者：QIAN Cheng LI Kun GUO Xue-yi LIU Bin LONG Zheng-yi LIU Yong 钱铖;李昆;郭学益;刘彬;龙郑易;刘咏(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;School of Metallurgy and Environment,Central South University,Changsha 410083,China)

机构地区：[1]State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China [2]School of Metallurgy and Environment,Central South University,Changsha 410083,China

出　　处：《Journal of Central South University》2020年第4期1146-1157,共12页中南大学学报（英文版）

基　　金：Project(51671217)supported by the National Natural Science Foundation of China;Project(2016YFB0700302)supported by the National Key Research and Development Plan of China。

摘　　要：For developing new binder phase with high performance, Co-Ni-Fe alloy was used as binder in cemented carbides. The mechanical properties of WC-CoNiFe and WC-Co cemented carbides with different grain sizes were studied. The results show that the reprecipitation of WC-CoNiFe is inhibited compared with that of WC-Co during sintering process, and the grains in WC-CoNiFe cemented carbides are more of smooth shape, resulting in a slightly lower hardness and higher transverse rupture strength. With the increase of the grain size, the hardness of the two cemented carbides decreases, and the transverse rupture strength increases. However, the slope values of K in Hall-Petch relationship are higher in WC-CoNiFe than those in WC-Co, indicating the high toughness of medium entropy alloy Co-Ni-Fe.为了开发高性能的新型粘结相,Co-Ni-Fe合金被用作硬质合金中的粘结剂。本文研究了不同晶粒尺寸的WC-CoNiFe与WC-Co的力学性能的差异。结果表明,与WC-Co相比,在烧结过程中WC-CoNiFe的再沉淀得到抑制,WC晶粒更平整,造成硬度略低,抗弯强度增强。并且随着晶粒尺寸的变大,两种硬质合金的硬度变低,抗弯强度上升。而且,在霍尔-佩奇关系中,WC-CoNiFe的斜率值K高于WC-Co,表明中熵合金Co-Ni-Fe具有较高的韧性。

关 键 词：cemented carbides mechanical properties dissolution-reprecipitation Hall-Petch relationship medium entropy alloy 

分 类 号：TG135.5[一般工业技术—材料科学与工程]