时效处理对城市轨道交通铜基受电弓滑板组织与性能的影响

Effect of aging treatment on microstructure and properties of urban rail transit copper-based pantograph slider

采用粉末冶金法制备铜基受电弓滑板材料,在830℃下固溶2 h后水淬,然后在450~600℃下进行1~4 h时效处理。通过对不同时效温度和时间下材料的硬度、电阻率、冲击韧性和抗拉强度等性能的测试,以及微观组织与物相组成的观察与分析,研究铜基受电弓滑板材料的时效处理行为。结果表明:随时效时间延长,铜基滑板材料的硬度、冲击韧性和抗拉强度都先升高后降低,电阻率先下降然后略有升高;随时效温度升高,材料的各项性能均先提高后下降。时效处理前后材料断裂均以塑性断裂的方式进行,时效处理后拉伸断口韧窝更深,材料的冲击韧性更大。在500℃下时效3 h后,主要物相仍是铜和石墨,并产生纳米级的六方Cu_(10)Sn_3析出相,对基体产生强化作用,从而提高材料的各项性能,电阻率为0.147μ?·m,硬度HB为89,抗拉强度为355.68 MPa,冲击韧性为47.1 J/cm^2,可满足我国铜基受电弓滑板的使用要求。

Copper-based pantograph slider materials were prepared by powder metallurgy method, and proceed solution treatment at 830℃ for 2 h and water hardening treatment, and then aging treatment at 450 to 600℃ for 1-4 h. The aging treatment behaviors of copper-based pantograph slider materials were studied by testing the properties of the materials hardness, resistivity, impact toughness and tensile strength at different aging temperatures and times as well as observation and analysis of the microstructure and phase composition. The results show that, with increasing aging time, the hardness, impact toughness and tensile strength of copper-based pantograph slider materials increase firstly and then decrease, while the resistivity decreases firstly and then increases slightly. Various performance of copper-based pantograph slider materials all increase firstly and then decrease with increasing aging temperature. The fracture mechanisms of the materials both before and after aging treatment are plastic fracture, and the dimples after aging treatment are deeper, and the impact toughness is higher. After aging treatment at 500℃ for 3 h, the main phases are copper and graphite, and the nano hexagonal Cu10Sn3 phase precipitates, which can strengthen the matrix and improve the properties of the materials. The performance of materials with electrical resistivity of 0.147μΩ·m, hardness HB of 89, tensile strength of 355.68 MPa, impact toughness of 47.1 J/cm^2 can be obtained, which can meet the requirements of national standards.