粉末冶金制备碳纤维增强铁-铜基摩擦材料的组织与性能

以铁-铜为主组元,以石墨和MoS2为润滑组元,以Al2O3、SiC、锆英砂为摩擦组元,并添加不同质量分数的碳纤维,将原料混合均匀后经600 MPa冷压成形,然后在氢气气氛下热压烧结2 h(980℃,2~3 MPa),制备得到碳纤维增强铁-铜基摩擦材料,并对其硬度、相对密度、显微组织、摩擦磨损性能进行研究。结果表明:铁-铜基体上均匀分布着耐磨的陶瓷相及润滑组元,铁-铜基体有部分固溶,碳纤维掩埋在基体和摩擦组元间。当碳纤维质量分数为2%~4%时,所制备的摩擦材料硬度为HV 102.2~118.6,相对密度为90.4%~92.6%,摩擦系数为0.56~0.60,磨损失重量最小。该摩擦材料的磨损主要为磨粒磨损,伴随少量粘着磨损。碳纤维可以强化基体,钉扎摩擦组元,在摩擦磨损过程中隔断犁沟,降低材料磨损。

Microstructure and properties of carbon fiber reinforced Fe-Cu based friction materials prepared by powder metallurgy

The carbon fiber reinforced Fe-Cu based friction materials were prepared by cold press molding at 600 MPa and hot pressed sintering at 980 and 2℃~3 MPa for 2 h in hydrogen atmosphere, using Fe-Cu as the main component, graphite and MoS₂ as the lubrication component, and Al₂O₃, SiC, and zirconium sand as the friction component with adding carbon fiber in different mass fraction. The hardness, relative density, microstructure, and friction and wear properties of the friction materials were investigated in the paper. The results show that the wear-resisting ceramic phase and the lubricating component are uniformly distributed on the Fe-Cu matrix, and the Fe-Cu matrix is partially solid-dissolved, and the carbon fiber is buried between the matrix and the friction component. When the mass fraction of carbon fiber is 2%~4%, the hardness of the prepared friction material is HV 102.2~118.6, the relative density is 90.4%~92.6%, the friction coefficient is 0.56~0.60, respectively, and the accumulated wear loss weight is the smallest. The wear mechanism of friction materials is mainly abrasive wear, accompanied by a small amount of adhesive wear. The carbon fiber can strengthen the matrix, nail the friction components, separate the furrow, and reduce the wear during the friction process.