高温热震条件下铜基粉末冶金闸片的组织演变及氧化机理研究  

Study on the Microstructure Evolution and Oxidation Mechanism of Copper-based Powder Metallurgy Brake Pads under High Temperature Thermal Shock Conditions

作　　者：马运章 关淑娟 MA Yunzhang;GUAN Shujuan(Tieke Zongheng Tianjin Technology Development Co.,Ltd.,Tianjin 301709,China)

机构地区：[1]铁科纵横天津科技发展有限公司,天津301709

出　　处：《兰州交通大学学报》2025年第2期78-85,共8页Journal of Lanzhou Jiaotong University

基　　金：中国铁道科学研究院基金(2023YJ007)。

摘　　要：对铜基粉末冶金闸片进行了900℃下的热震循环试验,研究了铜基粉末冶金闸片的外观以及微观组织变化,并对摩擦块表面氧化物形貌及成分进行分析,阐述了氧化机理。铜基粉末冶金闸片的主要成分为铜粉、铁粉、石墨、铬铁等。结果表明:经过5次热震循环后,粉末冶金闸片表面发生氧化,变成浅灰色,10次后,氧化程度加剧,出现轻微的裂纹;5次热震循环后摩擦块表面氧化物未完全覆盖表面,主要为CuO、Cu_(2)O、FeCr_(2)O_(4)和Fe_(2)O_(3)的混合物,10次热震循环后摩擦块表面基本被氧化物覆盖,主要为CuO和Cu_(2)O。经过热震循环后,铁粉颗粒与铜基体的界面更加模糊,石墨表面形态变得粗糙;摩擦块表面裂纹形成的主要原因与氧化膜快速生长所引发的应力以及各组元热膨胀系数的差异性有关。Thermal shock cycling tests were conducted on copper-based powder metallurgy brake pads at 9oo C,and the appearance and microstructural changes of the copper-based powder metallurgy brake pads were studied.The morphology and composition of the surface oxides on the friction block were analyzed,and the oxidation mechanism was elucidated.The main components of copper-based powder metallurgy brakes are copper powder,iron powder,graphite,ferrochrome.The results indicated that after 5 thermal shock cycles,the surface of the powder metallurgy brake pad got oxidized and turned light gray.After 10 cycles,the degree of oxidation increased,and slight cracks appeared.After 5 thermal shock cycles,the surface oxides on the friction block did not fully cover the surface,were mainly a mixture of CuO,Cu_(2)O,FeCr_(2)O_(4)and Fe_(2)O_(3).After 10 cycles,the surface of the friction block was mostly covered by oxides of CuO and Cu_(2)O.After thermal shock cycling,the interface between the iron powder particles and the copper matrix became more blurred,and the surface morphology of the graphite became rough.The main reason for the formation of cracks on the surface of the friction block is related to the stress caused by the rapid growth of the oxide film and the difference in thermal expansion coefficients of the components.

关 键 词：铜基粉末冶金闸片 热震 微观组织 氧化机理 

分 类 号：TF125[冶金工程—粉末冶金]