定向凝固Cu-Cr自生复合材料显微组织和力学、电学性能研究

Study on the Microstructure, Tensile Properties and Electrical Conductivity of Directionally Solidified Cu-Cr In-Situ Composites

运用Bridgman技术制备Cu Cr自生复合材料 ,研究了凝固方法和凝固速率对凝固组织及性能的影响 ,分析了复合材料性能提高的原因。结果表明 :复合材料的组织是由α基体相和分布于α相间的纤维状共晶体复合组成 ,随凝固速率增加 ,各组织生长定向性变好且径向尺寸均得到细化 ;致密、均匀、规整排列的组织减少了横向晶界 ,而复合材料的断裂受共晶增强体的断裂控制 ,使得复合材料的强度、塑性、导电性均高于体积凝固试样 ,使复合材料的综合性能提高。

The Cu-Cr In-situ Composites are manufactured by Bridgman method, and the influence of solidification methods and solidification rates on the structure and its effects on properties are studied. The reasons of the improved properties are analysed. It is shown that the structure of the composites consists of α(Cu) matrix phase and fibre-like(α+β)eutectics which set in the α phase. With the increase of the solidification rates, the directional tendency of the phases becomes well and structure thin. The structure is distributed evenly and regularly so that the transverse boundaries of the crystal reduce, and the fracture of the composites is controlled by the fracture of the eutectic as reinforce phase, so the tensile properties and electrical conductivity of the composites are higher than the one of the normally solidified alloy. At last, the compositive properties are improved.