Effects of rare-earth additions on the microstructure and strength of Cu–Ag composites

The filamentary composites of Cu–6 wt.% Ag and Cu–12 wt.% Ag containing rare-earth elements with different contents were prepared by casting and cold drawing. The microstructure was observed and the tensile strength determined for the composites at different draw ratios. The rare-earth elements of 0.05–0.15 wt.% in Cu–6 wt.% Ag and 0.1–0.3 wt.% in Cu–12 wt.% Ag result in large spacing or low density of the filamentary interface in the composites. Some hard compound particles exist in the composites containing rare-earth elements and result in high stress concentration. The rare-earth additions in the composites can improve the strength at low drawing degrees but reduce the strength at high drawing degrees.