过渡族金属碳化物在WC-Co硬质合金中的界面偏析与固溶行为

过渡族金属碳化物是最常见的硬质合金微观组织结构与性能调控添加剂,添加剂在硬质合金中赋存状态的研究是WC晶粒生长抑制机理研究的基础,也是硬质合金材料与工艺设计的基础。从基于第一性原理计算的理论研究、基于高分辨透射电镜和原子探针层析法的实验观察分析等2个方面,综述了过渡族金属碳化物在WC/β(钴基固溶体粘结相)相界偏析行为的研究现状。基于过渡族金属碳化物在硬质合金中晶界与相界的偏析行为、在硬质相与粘结相中的固溶行为,讨论了硬质合金中WC晶粒生长机理与晶粒生长抑制机理以及过渡族金属碳化物对硬质合金性能的影响机理,提出了硬质合金材料与工艺设计的建议。

Boundary Segregation and Solid Solution Behaviors of Transitional Metal Carbides in WC-Co Cemented Carbides

Acting as the microstructure and property modulation, transitional metal carbides are the most common additives in cemented carbides. Research on the occurrence and distribution sate of the transitional metal carbides in WC- Co cemented carbides is the basis of the WC grain growth inhibition and the materials and techniques design. From the aspects of first-principles calculation and high-resolution transmission electron microscopy and atom probe tomography observation and analysis, segregation behavior of the transitional metal carbide additives at the WC//3 （Co-based solid solution） phase boundary in WC-Co cemented carbides was summarized. The WC/WC grain boundary and WC/I3 phase boundary segregation behaviors and the WC and binder phase solid solution behaviors of the transitional metal carbides in WC-Co cemented carbides were discussed. The mechanisms of the WC grain growth and grain growth inhibition and the improvement in the properties of cemented carbides were discussed. Suggestions for the materials and techniques design are proposed.