铜基粉末冶金摩擦材料粘接层失效机理研究

Study on the Failure Mechanism of Cu-based PM Friction Material Bonding Layer

因摩擦材料粘接面失效导致的摩擦体脱落现象给铁路客运安全带来隐患。文中采用摩擦块厚度分别为21、15、9 mm的燕尾型铜基闸片进行1∶1制动动力试验,研究了不同磨耗状态的闸片制动时摩擦块粘接层温度和温升的特点,及其与粘接层形貌和强度的关系。结果表明,摩擦块在制动时承受反复高温载荷作用,粘接面附近在热应力作用下产生疲劳裂纹,降低了粘接面的剪切强度。摩擦块厚度越薄,制动时粘接面的温度越高且温升越快,加速了疲劳裂纹的产生,更容易发生摩擦体脱落。

The friction particle coming off caused by the failures of bonding layer materials is a safety hazard to the railway transport.This paper uses dovetail copper-based brake pads with thicknesses of 21 mm,15 mm,and 9 mm to conduct a 1:1 braking dynamic test to explore the characteristics of the temperature and temperature raising during the brake process among the different friction particle thickness,and the relationship between the microstructure of the bonding layer and the bonding strength.The analysis shows that the friction block is subjected to repeated high-temperature loads,and the bonding interface generated fatigue cracks under the action of thermal stress,which reduced the shear strength of the bonding interface.The lower thickness of the friction particle caused the higher temperature and temperature raising of the bonding interface,which accelerated the generation of the fatigue cracks,made the friction particles coming off easily.