Effect of trace yttrium on properties and microstructure of Cu-0.6Cr-0.15Zr-0.05Mg-0.02Si Alloy

Effect of rare earth yttrium on the properties and microstructure of Cu-0.6Cr-0.15Zr-0.05Mg-0.02Si alloy was investigated. The results showed that Cu-0.6Cr-0.15Zr-0.05Mg-0.02Si alloy obtained good comprehensive performance after 80% deformation and then aging at 480 degrees C for 1h, the hardness and electrical conductivity reached 152HV and 85.5%IACS, respectively. The aging time of Y-containing alloy for attaining peak hardness was postponed and the precipitates were finer (2-4nm) and interparticle spacing was shorter than ones of Y-free alloy. The hardness and electrical conductivity of the Y-containing alloy after 80% deformation and then aging at 480 degrees C for 45 min reached 174HV and 82.1%IACS, respectively. The tensile fractures of the two alloys which exhibits the obvious feature of tough fracture.