C/C复合材料表面改性薄膜的制备及摩擦磨损性能研究

Preparationand friction and wear property study of C/C composites surface modification films

采用先驱体转化法在C/C复合材料基底表面制备了厚度为3~5μm的SiC薄膜和Si3N4薄膜;用球-盘对磨的方式测试了C/C复合材料基底、SiC薄膜和Si3N4薄膜在干态下的摩擦磨损性能。结果表明,制备的SiC薄膜和Si3N4薄膜表面结构均匀致密,无明显缺陷。C/C复合材料基底的平均摩擦系数为0.17,磨损率为1.93×10^-4 mm^3·N^-1·m^-1;SiC薄膜的平均摩擦系数为0.13,磨损率为0.78×10^-4 mm^3·N^-1·m^-1;Si3N4薄膜的平均摩擦系数为0.12,磨损率为0.45×10^-4 mm^3·N^-1·m^-1。与C/C复合材料基底相比,SiC薄膜和Si3N4薄膜的摩擦系数和磨损率都有所降低。C/C复合材料基底的摩擦磨损机理主要以磨粒磨损和粘着磨损为主,SiC和Si3N4薄膜的摩擦磨损机理主要以疲劳磨损为主。

The SiC and Si3N4 films with 3~5μm thickness were prepared on the surface of C/C composite substrate by precursor transformation.Friction and wear properties of C/C composite substrate and SiC and Si3N4 films were investigated with a ball-on-disk tribometer in dry air.The results show the uniform and dense surface structure of SiC film and Si3N4 film without obvious defects.The average friction coefficient and wear rate of C/C composite substrate were 0.17 and 1.93×10^-4 mm^3/(N·m).The average friction coefficient and wear rate of SiC film were 0.13 and 0.78×10^-4 mm^3/(N·m).The average friction coefficient and wear rate of Si3N4 film were 0.12 and 0.45×10^-4 mm^3/(N·m).The friction coefficient and wear rate of films were reduced compare with the C/C composite substrate.The friction and wear mechanism of C/C composite substrate was mainly based on abrasive and adhesive wear,while SiC and Si3N4 film was mainly based on fatigue wear.