Mo_2C改性C/C-Cu复合材料的组织及载流摩擦磨损性能

Structure and tribological property with electric current of Mo_2C modified C/C-Cu composites

采用熔盐法在低密度炭/炭(C/C)坯体内孔表面制备了Mo_2C涂层,然后通过无压熔渗制备了C/C-Cu复合材料,研究了C/C-Cu复合材料的组织结构及载流摩擦磨损性能。结果表明:熔融Cu可自发渗入制备了Mo_2C内涂层的C/C坯体,复合材料中Cu相与C/C坯体形成相互贯穿的连通网络结构,Mo_2C涂层与Cu和热解炭(PyC)间均有良好的界面结合,反应生成Mo_2C过程中的催化石墨化及应力石墨化共同作用使C/C-Cu复合材料中Mo_2C涂层附近PyC的有序度提高。随载荷增大,C/C-Cu复合材料的摩擦系数逐渐降低,体积磨损率增大,而对偶的质量损失逐渐降低;载荷较大时材料磨损表面被摩擦膜覆盖的面积增大,但因粘着磨损摩擦膜的粗糙程度提高。材料磨损过程中还发生了氧化磨损,且载荷增大磨损表面O含量提高。

Mo_2C coating was fabricated throughout the low-density carbon/carbon（C/C）preform from inside by a molten salt method,and then C/C-Cu composite was obtained by pressureless infiltration.The structure and tribological property with electric current of C/C-Cu composite were studied.The results show that molten Cu infiltrates into the Mo_2C-modified C/C preform spontaneously and retains interpenetrating network structure with the C/C preform.The Mo2 C coating presents good interfacial bonding with Cu and PyC,and pyrolytic carbon（PyC）near the Mo2 C coating presents an order degree improvement as a result of catalytic and stress graphitization in process of generating Mo2 C.With the increase of load,the friction coefficient of C/C-Cu composite decreases,the volume wear rate increases,while the mass loss of counter part decreases gradually.The worn surface under higher load is coated by a more continuous friction film,while roughness of the worn film increases due to adhesion wear.The material experiences oxidation wear during the wear process,and the content of oxygen on wear surface increases with the increase of load.