稀土对纤维相Cu-12%Ag合金组织性能的影响

为研究稀土微合金化在纳米纤维强化Cu-Ag合金中的作用，制备了纤维相增强Cu-12%Ag和Cu-12%Ag-0.3%RE合金．采用冷拉拔结合中间热处理方法制备该类合金，观察并测定了不同变形程度下稀土元素对合金显微组织、力学性能和电学性能.实验结果表明，随变形程度增大，合金硬度和强度上升，相对电导率下降.稀土元素可增加原始组织枝晶轴间距、共晶体数量及共晶体中Ag的质量分数，提高合金的硬度，但对合金抗拉强度没有明显影响.在较低的变形程度范围内，稀土元素使合金导电性能略有降低.在大变形范围内，稀土元素可在一定程度上改善导电性能.

Effects of rare earth additions on microstructure and properties of Cu-12%Ag filamentary composites

To investigate the influences of rare earth additions on the microstructure,Cu-12%Ag and Cu-12%Ag-0.3%RE filamentary composites were prepared by cold drawing and intermediate heat treatments.The mechanical properties and electrical conductivity at various levels of drawing strain were measured and the microstructure was observed.The results show that the ultimate tensile strength and hardness of the composites increase but the electrical conductivity decreases with the increasing draw ratio.Rare earth elements in the Cu-12%Ag increase the interval of dendritic arms,the volume fraction of eutectic structure,the mass percent of Ag in eutectic colonies and the hardness level of the composite but have an insignificant effect on the ultimate tensile strength.Rare earth elements in the Cu-12%Ag slightly decrease the electrical conductivity in the range of low draw ratio but increase the electrical conductivity in the range of high draw ratio.