铜增韧Mo_(2)BC陶瓷的力学性能和摩擦学性能  

Mechanical and tribological properties of Mo_(2)BC ceramic toughened by copper

作　　者：张智源[1,2] 王帅 逄显娟[1] 刘娟[1] 祝林[1] 杜三明 张永振[1] ZHANG Zhiyuan;WANG Shuai;PANG Xianjuan;LIU Juan;ZHU Lin;DU Sangmin;ZHANG Yongzhen(National United Engineering Laboratory for Advanced Bearing Tribology,Henan University of Science and Technology,Luoyang 471023,China;School of Materials Science and Engineering,Henan Institute of Technology,Xinxiang 453003,China)

机构地区：[1]河南科技大学高端轴承摩擦学技术与应用国家地方联合工程实验室,河南洛阳471023 [2]河南工学院材料科学与工程学院,河南新乡453003

出　　处：《中南大学学报（自然科学版）》2024年第8期2867-2878,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(92266205,51805513);中国博士后科学基金资助项目(2022M712942);河南省自然科学基金资助项目(222300420436)。

摘　　要：采用快速热压反应烧结法制备高强韧Mo_(2)BC/Cu陶瓷基复合材料。研究铜含量对Mo_(2)BC/Cu复合材料的微观组织、力学性能和摩擦学性能的影响,并对其增韧机制和磨损机理进行分析。研究结果表明:Cu均匀地分散在Mo_(2)BC基体中,具有细化晶粒的作用。Mo_(2)BC/Cu复合材料中铜可以添加的最大质量分数为7.5%。随着铜含量的增加,Mo_(2)BC/Cu复合材料的弯曲强度和断裂韧性增加。当Cu质量分数为7.5%时,复合材料的弯曲强度和断裂韧性最高,分别为625.1 MPa和7.4 MPa·m^(1/2),与Mo_(2)BC陶瓷相比,分别提高了24%和62%,其主要的增韧机制为铜的塑性变形、晶粒拔出、桥接效应和裂纹的偏转。此外,铜的添加还可以明显提高Mo_(2)BC/Cu复合材料的摩擦磨损性能。当Cu质量分数为2.5%时,复合材料的摩擦因数可低至0.36,磨损量最小,耐磨性最优,其主要的磨损机制为轻微的二体磨粒磨损和氧化磨损。High strength and toughness Mo_(2)BC/Cu ceramic matrix composites were fabricated by in-situ reaction fast hot-pressing sintering method.The effect of Cu content on the microstructure,mechanical and tribological properties was investigated.The wear and toughening mechanisms of the composites were discussed as well.The results show that Cu is distributed uniformly in the Mo_(2)BC matrix and plays a role of refining grains.The maximum mass fraction of Cu addition is confirmed to be7.5%for Mo_(2)BC/Cu composites.The flexural strength and fracture toughness of as-sintered composites increase with the increase of Cu content.When the mass fraction of Cu is 7.5%,the flexural strength and fracture toughness of Mo_(2)BC/Cu composites have the highest values of 625.1 MPa and 7.4 MPa·m^(1/2),which increase by 24%and 62%compared with that of Mo_(2)BC ceramic,respectively.Plastic deformation,grain pull-out,crack bridging and deflection are the main toughening mechanisms.The addition of Cu significantly improves the friction and wear properties of Mo_(2)BC/Cu composites.When the mass fraction of Cu is 2.5%,the friction coefficient of the composite can be as low as 0.36,showing that the wear loss is the lowest and the wear resistance is the best.The main wear mechanisms are slight two-body abrasion and oxidation wear.

关 键 词：陶瓷基复合材料 Mo_(2)BC 高强韧 摩擦磨损 

分 类 号：TH117.1[机械工程—机械设计及理论] TH142.2[一般工业技术—材料科学与工程]