Ti_3SiC_2系材料的载流磨损特性及机理  

Current-Carrying Wear Characteristics and Mechanisms of Ti_3SiC_2 Class Materials

作　　者：黄振莺[1] 翟洪祥[1] 刘新[1] 艾明星[1] 周炜[1] 

机构地区：[1]北京交通大学机械与电子控制工程学院,北京100044

出　　处：《稀有金属材料与工程》2007年第A02期434-437,共4页Rare Metal Materials and Engineering

基　　金：国家自然基金(50472045);国家"863"计划项目(2003AA332080);北京交通大学博士生科技创新基金(48014)资助

摘　　要：研究了三元层状化合物钛硅碳(Ti_3SiC_2)和钛铝碳(Ti_3AlC_2)材料的载流磨损特性,探讨了在大电流、热应力和摩擦力的交互和耦合作用下Ti_3SiC_2系材料的支配性磨损机理。试验在盘-块式大功率载流高速摩擦试验机上进行,用A3钢盘为对磨体;滑动速度为20m/s,法向压强为0.4～0.8 MPa,电流强度为0,50和100 A。结果表明,在适当的速度和载荷条件下,Ti_3SiC_2系材料表现出良好的载流摩擦学特性。但载流条件下的磨损率都比非载流条件下的大,且随电流强度而增大。通过SEM&EDS观察、分析,载流条件下的Ti_3SiC_2系材料的磨损主要由微电弧烧蚀与机械摩擦的交互作用及热-力耦合作用两部分共同影响。微电弧烧蚀作用引起Ti_3SiC_2系材料表层氧化、熔融和分解以及亚表层裂纹,因而耐磨性发生改变。通电条件下的电热效应和摩擦热的耦合作用也对Ti_3SiC_2系材料的耐磨性产生影响。力-电-热的交互和耦合作用哪部分占主导机制取决于Ti_3SiC_2系材料的物理参数及载荷、速度等外部条件因素。The current-carrying wear characteristics of Ti3SiC2 and Ti3AlC2, which belong to the ternary carbides, were studied. And the wear mechanisms of Ti3SiC2 class materials with the interaction and coupled action under high-current, thermal stress and friction force were discussed. The tests were carried out using a block-on-disk type, current-carrying, high speed friction tester, with sliding speeds of 20 m/s, normal pressures range in 0.4-0.8 MPa, and the current intensity of 0 A, 50 A and 100 A, respectively. The results showed that the Ti3SiC2 class materials showed good current-carrying tribological properties under the appropriate sliding speeds and normal pressures However, the wear rates of Ti3SiC2 or Ti3AlC2 with current friction were larger than that without current, and increased with the increase of the current intensity. The friction surfaces were observed and analyzed using SEM ＆ EDS. It was found that, the wear rate of the Ti3SiC2 class materials with current friction was composed of two parts： the interaction of micro-arc ablation and mechanical friction, and the coupled action of thermal and mechanical effect. The micro-arc ablation causes the oxidation, melting and decomposition of the friction surface and the crack creating of the subsurface. This induces the changing of the wear property of Ti3SiC2 class materials. The coupled action of the electrothermal effect and the frictional heat also makes the wear property worse. Which one will be the main mechanism： the interaction or the coupled action of mechanical, electrical and thermal, is depended on the material parameters of Ti3SiC2 class as well as the mechanical parameters such as normal pressure and sliding speed

关 键 词：Ti3SiC2系材料 载流磨损 微电弧烧蚀 电热效应 交互作用 

分 类 号：O614.411[理学—无机化学]