C/N物质的量比和金属碳化物对TiCN-Ni合金体系润湿行为的影响  

Effects of C/N molar ratios and metal carbides on wetting behaviors of TiCN-Ni alloy system

作　　者：张立[1] 肖桥平 刘涛[1] 凌群 罗国凯 吴厚平[1] 崔焱茗 ZHANG Li;XIAO Qiaoping;LIU Tao;LING Qun;LUO Guokai;WU Houping;CUI Yanming(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2020年第11期3007-3018,共12页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51574292);湖南省自然科学基金资助项目(2019JJ40373)。

摘　　要：采用座滴法分别测量真空条件下Ni熔体与TiC0.4N0.6,TiC0.7N0.3,TiC0.7N0.3-29WC-12TaC和TiC0.7N0.3-29WC-12TaC-2Mo2C基体之间的接触角,采用扫描电镜和能谱分析仪分析润湿性测试后合金体系微观结构与成分变化。对Mo2C显著改善合金体系润湿性的机理、层状结构形成机理、WC和TaC在合金中作用行为等进行分析,提出液相烧结合金体系润湿性的改善方法及其综合评价方法。研究结果表明:该合金体系的初始接触角分别为24.5°,21.2°,19.8°和14.2°,4种基体中均形成了层次分明的富Ni和贫Ni层状结构,合金体系属于扩散和溶解驱动型润湿;在TiC0.4N0.6基体表面出现了Ni熔体显著蒸发及其在基体中扩散和渗透能力显著弱化的独特现象。The contact angles between Ni melt and TiC0.4N0.6,TiC0.7N0.3,TiC0.7N0.3-29WC-12TaC,TiC0.7N0.3-29WC-12TaC-2Mo2C substrate in vacuum were measured by sessile drop method.The microstructure and composition changes of the alloy systems after the wettability tests were observed and analyzed by scanning electron microscope and energy dispersive spectrometer.The mechanisms of substantially improved wettability of the alloy system by Mo2C and the formation of layered structure,and the behaviors of WC and TaC in the alloy were analyzed.Improvement and comprehensive evaluation methods for the wettability of alloys by liquid phase sintering were proposed.The results show that the initial contact angles of the above alloy systems are 24.5°,21.2°,19.8°and 14.2°respectively,driven by a diffusion-and solution-driven wetting mechanism.In the four substrates,a distinct Ni-rich and Ni-deficient layer structure is formed.For the TiC0.4N0.6 substrate,a unique phenomenon of significantly evaporation and significantly weakened diffusion and penetration ability of Ni melt is identified.

关 键 词：金属陶瓷 黏结金属 润湿性 接触角 层状结构 熔体渗透 

分 类 号：TG14[一般工业技术—材料科学与工程]