Development of high-electrical-conductivity and high-wear-resistance hypoeutectic Cu-Zr alloy SPS materials

This study aimed to develop hypoeutectic Cu-Zr bulk alloy materials with high electrical conductivity and wear resistance, and low processing cost, by spark plasma sintering (SPS). Starting raw materials for SPS were prepared with two different types of powders: high-pressure gas-atomized powder (HGA powder) and powder prepared by ball-milled method from commercial Cu powder and Cu-50 mass% Zr master alloy powder (BM powder). All of Cu-1, Cu-3, and Cu-5 at.% Zr alloy SPS materials prepared from these raw materials were of good consolidation. The structure, electrical conductivity, and wear resistance of the obtained SPS materials were examined. The SPS materials had a two-phase structure consisting of α-Cu and intermetallic Cu₅Zr phases. In the HGA-SPS material, fine Cu₅Zr grains were uniformly distributed in α-Cu. On the other hand, in the BM-SPS materials, coarse Cu₅Zr grains were heterogeneously distributed in α-Cu. Electrical conductivities of the SPS materials of the same composition prepared from different raw materials were comparable. The wear resistance followed the order of oxygen-free copper (OFC) < HGA-SPS < BM-SPS. SPS material prepared from the BM powder was found to have high electrical conductivity and wear resistance with low processing cost.