Effect of Zr addition on the microstructure and properties of Cu-10Cr in situ composites

The Cu-10Cr-0.4Zr alloy and the in situ composites based on the alloy were prepared. Microstructure evolution and mechanical properties of Cu-10Cr-0.4Zr in situ composites were investigated. The results showed that the addition of 0.4 wt.% Zr in the Cu-10 wt.% Cr in situ composites gave birth to smaller ascast Cr dendrites, which led to finer filaments at higher strain ratios. The ultimate strength of Cu-10Cr0.4Zr composites reached 1089 MPa at draw ratio of eta = 6.2. however that of Cu-10Cr prepared by the same procedure was only 887 MPa. The increasing strength of Cu-10Cr-0.4Zr in situ composites could be attributed to the combination of Hall-Petch strengthening of closely spaced Cr filaments, the strengthening effect of Zr and the strengthened Cu matrix. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.