Development of the precipitation and dispersion hardened powder metallurgy Cu-Ni-Si-Cr?+?Al 2O 3 alloy

摘要

AbstractA Cu-Ni-Si-Cr?+?Al2O3alloy, which combines the precipitation and dispersion hardening of the alloy, were produced by using the powder metallurgy (P/M) technique. To obtain the optimal properties of the alloy, a series of solution and aging treatments were conducted. Following heat treatments, the microstructural, thermal and mechanical properties of P/M produced Cu-Ni-Si-Cr?+?Al2O3alloy were investigated.The microstructural investigation indicates that the as hot-forged P/M Cu-Ni-Si-Cr?+?Al2O3alloy consists of Cu-Ni-Si-Cr powder (considered as grain A) and Cu-Al2O3powder (considered as grain B). After heat treatments, it is observed that massive Ni and minor Si elements from grain A diffuse to grain B and react with each other, resulting in the formation of the β-Ni3Si strengthening phases in both grains. Also, Al2O3dispersoids, which disperse in grain B, provide the high thermal stability in grain size. Therefore, the P/M-produced copper alloy developed in this study has a combination of the better thermal stability in relation to grain size, high strength or hardness and high thermal conductivity, which offers possible applications at elevated temperatures.Highlights?A Cu alloy, combining the precipitation and dispersion hardening, were produced.?P/M technology was used to produce the alloy.?Hot forging and various heat treatment processes were conducted to the alloy.?This alloy provides the better thermal stability in grain size.?Also, a good combination of thermal property, strength and grain size is obtained.]]>