烧结工艺对铜石墨受电靴材料性能影响及微观组织研究

Effect of Sintering Process on Properties of Copper-graphite Collector Shoe Material and Research on Its Microstructure

针对磁浮轨道交通受电靴滑块的使用性能要求,用粉末冶金法制备了铜石墨材料。在300 MPa的压力下常温压制成形,之后在氢气保护气氛下通过不同的升温方式分别进行880℃×1 h和920℃×2 h烧结,冷却至室温后,再以300 MPa的压力进行复压。研究了烧结工艺对材料性能的影响,并对材料的微观组织结构进行了分析。结果表明,适当提高材料的烧结温度和烧结时间,可提高材料的力学性能。拉伸断裂以脆性断裂为主,包含着局部的韧性断裂,层片状的石墨夹杂降低了材料的强度。基体中存在的位错、层错和孪晶有益于材料的力学性能。

Aimed at using property require of maglev, a type of copper-graphite collector shoe material was prepared by means of the powder metallurgy method. Each mixture of the investigated powders was formed by cold pressing at 300 MPa and sintered by two different processes （880℃×1 h and 920℃×2 h） in hydrogen atmosphere. After specimens were cooled to room temperature with the furnace, repression was operated at 300 MPa. The influences of sintering process on mechanical properties of the copper-graphite composite were studied. Micrographs were analyzed. The results show that higher relative density and lower porosity content can be obtained due to sintering time and temperature increasing, heating-up method improving.The tensile failure is mainly brittle fracture,whose part is tough hess fracture. Density, hardness and tensile strength all increase with the decrease of porosity. Dislocations, faults and twins in metallic matrix are advantageous to mechanical property of the materials.