刹车速度对C/C-SiC复合材料摩擦磨损性能的影响

EFFECT OF BRAKING SPEED ON FRICTION AND WEAR BEHAVIORS OF C/C-SiC COMPOSITES

对反应熔体渗透工艺制备的C/C-SiC复合材料,在MM-1000型摩擦磨损试验机上进行了模拟飞机制动刹车实验,重点研究了C/C-SiC复合材料在不同刹车速度下的摩擦磨损性能。研究表明:随着刹车速度的增加,C/C-SiC复合材料的摩擦系数先少许增加然后再减小,在10m/s时达到最大值0.52。磨损率在低速时保持较低的数值,随着刹车速度的增加呈线性增加,但仍小于C/C复合材料的磨损率,表明C/C-SiC复合材料具有优良的耐磨损性能。当刹车速度超过20m/s时,由于能载水平较高,摩擦表面出现犁沟现象并形成大量球状磨屑,摩擦系数急剧减小。

C/C-SiC composites were fabricated by the reaction melt infiltration method. Braking tests were carried out on an MM-1000 test machine simulating airplane braking. The friction and wear behaviors of C/C-SiC composites at different braking speeds were investigated. The experimental results show that the coefficient of friction increases to the maximum value of 0.52 at 10 m/s and then falls afterwards with the increase of braking speed. The wear rate remains low at low braking speeds and increases linearly with the increase of the braking speed, which demonstrates that the C/C-SiC composites have excellent wear resistance in comparison with C/C composites. Due to the high braking energy, ploughs appear on the friction surface and a large amount of spherical wear debris forms; therefore, the coefficient of friction decreases sharply when the braking speed exceeds 20 ntis.