China Mechanical Engineering ›› 2022, Vol. 33 ›› Issue (19): 2288-2297.DOI: 10.3969/j.issn.1004-132X.2022.19.002

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Study on Crack Repair Performance of Si3N4/TiC/ZrSi2 Ceramic Tool Materials

ZHANG Shuai;CHEN Zhaoqiang;XIAO Guangchun;YI Mingdong;ZHANG Jingjie;ZHOU Tingting;XU Chonghai   

  1. School of Mechanical and Automotive Engineering,Qilu University of Technology (Shandong Academy of Sciences),Jinan,250353
  • Online:2022-10-10 Published:2022-10-20

Si3N4/TiC/ZrSi2陶瓷刀具裂纹愈合性能研究

张帅;陈照强;肖光春;衣明东;张静婕;周婷婷;许崇海   

  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
  • 通讯作者: 陈照强(通信作者),男,1978年生,教授。研究方向为陶瓷刀具材料。E-mail:czq@qlu.edu.cn。
  • 作者简介:张帅,男,1996年生,硕士研究生。研究方向为陶瓷刀具、自修复陶瓷。
  • 基金资助:
    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)

Abstract: To solve the problems that ceramic tools were sensitive to cracks, ZrSi2 crack repairing agent was added into Si3N4/TiC ceramic tool material matrix, which made ceramic tools have crack repairing ability. When ZrSi2 content was as 10% (volumn fraction), Si3N4/TiC/ZrSi2 ceramic tool materials had better comprehensive properties, with flexural strength of 815 MPa, fracture toughness of 8.06 MPa·m1/2, 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 Si3N4/TiC-based ceramic materials with ZrSi2 as repair agent were studied. The research shows that the flexural strength of Si3N4/TiC/ZrSi2 prefabricated crack specimen with 10% ZrSi2 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 300~350 μm is completely repaired, and an oxide layer mainly composed of ZrO2 and SiO2 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, ZrSi2, a healing agent at the crack and the surface of the material, preferentially reacts with oxygen to generate ZrO2 and SiO2, which heal the crack on the surface of the material and restore the strength of the crack sample. At the same time, during cutting, ZrO2 and SiO2, oxidation products of ZrSi2 at the cracks and material surfaces, may repair the crack in time and improve the wear resistance of the tool. 

Key words: ceramic tool, mechanics property, microstructure, crack repair

摘要: 针对陶瓷刀具对裂纹敏感的问题,在Si3N4/TiC陶瓷刀具材料基体中添加ZrSi2裂纹愈合剂,使陶瓷刀具具有了裂纹自愈合能力。当ZrSi2的体积分数为10%时,Si3N4/TiC/ZrSi2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·m1/2,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ZrSi2为愈合剂的Si3N4/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ZrSi2体积分数为10%的Si3N4/TiC/ZrSi2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300~350 μm的裂纹完全愈合,并且试样表面形成了一层以ZrO2和SiO2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ZrSi2优先与氧气发生反应生成ZrO2、SiO2,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ZrSi2的氧化产物ZrO2和SiO2 可以及时修复裂纹,提高刀具的耐磨性。

关键词: 陶瓷刀具, 力学性能, 微观结构, 裂纹愈合

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