铜基粉末冶金摩擦材料高温疲劳磨损规律

Study of High Temperature Fatigue Wear of Copper Powder Metallurgy (Cu-PM)Friction Material

研究了高速列车用铜基粉末冶金多孔摩擦材料的高温摩擦磨损性能。在PlintTE77高温疲劳试验机上对该材料进行了高温磨损性能测试 ,工况分别为 :室温 ,10 0℃ ,2 0 0℃ ,3 0 0℃ ,3 5 0℃ ,5 0 0℃ ;法向载荷为 :2 0 0N ,45 0N ,等12种工况 ;振动频率为 :4Hz ;移动幅值为 :± 5mm ;并对摩擦后的磨痕进行了SEM分析 ,发现 :(1)在 2 0 0N ,3 0 0℃时出现了粘压的多源弧形裂纹 ,这和冲击时的沿树枝晶裂纹截然不同 ;(2 )在 45 0N ,3 0 0℃时 ,磨痕表面出现了球状的石墨颗粒层 ,这起到了极好的润滑作用 ,使得 3 0 0℃时磨损较低。 (3 )在 45 0N ,3 5 0℃时 ,有沿磨痕方向的长条裂纹出现 ;(4 )在不同荷载 5 0 0℃时 ,发生了负磨损 ,即摩擦材料粘附到对偶材料上 ,由于新的氧化面的形成摩擦系数是最高的。

High temperature friction wear properties of Cu PM for high speed train were investigated by Plint TE77 high temperature fatigue equipment.The experiment parameters were room temperature,100℃, 200℃,300℃,350℃,500℃;forces 200N, 450N; vibration frequency 4Hz; sliding displacement ±5mm.The wear scar after 15 000 cycles was analyzed by SEM.The results show:(1)there is multi sources arc crack at 200N, 300℃,it is different to impact crack with tree shape;(2)there is graphite coating on the surface,it is a good lubrication coating,it made a less wear at 450N,300℃; (3)there is a strip crack along wear scar after 15 000 cycles at 450N, 300℃; (4)there is negative wear,that is,the friction material adhere to the match material at 500℃,various pressures,but the coefficient of friction is the biggest.At last,the wear rule was fitted roughly.