通过冷拉拔应变制备了纤维相强化的Cu-6%Ag(质量分数,下同)合金,研究了不同应变条件下合金的显微组织和电阻率变化规律,讨论了应变对Cu-6%Ag合金导电性能的影响机制。随应变程度的增加,原始组织中的Cu基体晶粒、不平衡共晶体及次生相粒子最终演变成细密的纤维结构,合金电阻率上升。次生相界面、共晶体与Cu基体界面及位错对电子散射作用程度的变化导致了合金电阻率在不同变形程度范围内有不同的变化规律。当变形超过一定程度后,电阻率升高规律与来自较高Ag含量合金中纤维相尺度进入纳米数量级的界面散射模型相符。
Cu-6 wt%Ag filamentary composite was prepared by cold drawing. The characteristics of filamentary microstructure and electrical resistivity under different strain condition were investigated and the effect of strain on the electrical conductivity was discussed. With increasing the draw ratio, the Cu-rich dendrites, the eutectic colonies and the Ag precipitates in the as-cast and homogenized structure develop into the fine filamentary structure, resulted in the increase of electrical resistivity. The change in the electronic scattering effect of the phase interface between Ag precipitates and Cu grains and the interface between eutectic filamentary bundles and Cu matrix in the alloy against the dislocation resulted in the change in the electrical resistivity of alloy for different strain condition. For high draw ratios, the change of the electrical resistivity with strain is generally in accord with the interfacial scattering model proposed in the presented investigation on the composites with higher Ag contents when the filamentary structure evolves into nanoscale.