Si_(3)N_(4)/TiC/ZrSi_(2)陶瓷刀具裂纹愈合性能研究  

Study on Crack Repair Performance of Si_(3)N_(4)/TiC/ZrSi_(2) Ceramic Tool Materials

作　　者：张帅 陈照强[1] 肖光春[1] 衣明东[1] 张静婕[1] 周婷婷[1] 许崇海[1] ZHANG Shuai;CHEN Zhaoqiang;XIAO Guangchun;YI Mingdong;ZHANG Jingjie;ZHOU Tingting;XU Chonghai(School of Mechanical and Automotive Engineering,Qilu University of Technology(Shandong Academy of Sciences),Jinan,250353)

机构地区：[1]齐鲁工业大学(山东省科学院)机械与汽车工程学院,济南250353

出　　处：《中国机械工程》2022年第19期2288-2297,共10页China Mechanical Engineering

基　　金：山东省自然科学基金(ZR2020ME155);山东省重点研发计划(2019GGX104084,2020CXGC011004);国家自然科学基金(52075276);济南市高校创新团队项目(2018GXRC005)。

摘　　要：针对陶瓷刀具对裂纹敏感的问题,在Si_(3)N_(4)/TiC陶瓷刀具材料基体中添加ZrSi_(2)裂纹愈合剂,使陶瓷刀具具有了裂纹自愈合能力。当ZrSi_(2)的体积分数为10%时,Si_(3)N_(4)/TiC/ZrSi_(2)陶瓷刀具材料具有较好的综合性能,其抗弯强度为815 MPa,断裂韧性为8.06 MPa·m^(1/2),维氏硬度为15.91 GPa,并且其相对密度可以达到99.72%。通过维氏硬度计在陶瓷刀具材料表面引入裂纹,研究了以ZrSi_(2)为愈合剂的Si_(3)N_(4)/TiC基陶瓷材料裂纹的最佳愈合参数和愈合机理。研究表明:添加ZrSi_(2)体积分数为10%的Si_(3)N_(4)/TiC/ZrSi_(2)预制裂纹试样,在空气气氛中800℃热处理60 min后,其抗弯强度可以恢复到光滑试样的92.02%,试样表面长度为300~350μm的裂纹完全愈合,并且试样表面形成了一层以ZrO_(2)和SiO_(2)为主要成分的氧化层。分析陶瓷刀具材料的裂纹愈合机理表明:在空气热处理过程中,部分在裂纹处和材料表面的愈合剂ZrSi_(2)优先与氧气发生反应生成ZrO_(2)、SiO_(2),这两种氧化物愈合了材料表面的裂纹,恢复了裂纹试样的强度。同时在切削过程中,部分在裂纹处和材料表面的愈合剂ZrSi_(2)的氧化产物ZrO_(2)和SiO_(2)可以及时修复裂纹,提高刀具的耐磨性。To solve the problems that ceramic tools were sensitive to cracks,ZrSi_(2) crack repairing agent was added into Si_(3)N_(4)/TiC ceramic tool material matrix,which made ceramic tools have crack repairing ability.When ZrSi_(2) content was as 10%(volumn fraction),Si_(3)N_(4)/TiC/ZrSi_(2) ceramic tool materials had better comprehensive properties,with flexural strength of 815 MPa,fracture toughness of 8.06 MPa·m^(1/2),Vickers hardness of 15.91 GPa and relative density of 99.72%.Cracks were introduced into the surface of ceramic tool materials by Vickers hardness tester,and the optimal repair parameters and repair mechanism of cracks in Si_(3)N_(4)/TiC-based ceramic materials with ZrSi_(2) as repair agent were studied.The research shows that the flexural strength of Si_(3)N_(4)/TiC/ZrSi_(2) prefabricated crack specimen with 10%ZrSi_(2) added may be restored to 92.02%of that of smooth specimen after heat treatment at 800℃for 60 min in air atmosphere,and the crack with the surface length of 300~350μm is completely repaired,and an oxide layer mainly composed of ZrO_(2) and SiO_(2) is formed on the surface of the specimen.The mechanism of crack repair of ceramic cutting tool materials is analyzed as follows:in the air heat treatment processes,ZrSi_(2),a healing agent at the crack and the surface of the material,preferentially reacts with oxygen to generate ZrO_(2) and SiO_(2),which heal the crack on the surface of the material and restore the strength of the crack sample.At the same time,during cutting,ZrO_(2) and SiO_(2),oxidation products of ZrSi_(2) at the cracks and material surfaces,may repair the crack in time and improve the wear resistance of the tool.

关 键 词：陶瓷刀具 力学性能 微观结构 裂纹愈合 

分 类 号：TG711[金属学及工艺—刀具与模具] TQ174.75[化学工程—陶瓷工业]