Microstructure and properties of Cu−2Cr−1Nb alloy fabricated by spark plasma sintering

Abstract

Cu−2Cr−1Nb alloy was fabricated by spark plasma sintering (SPS) using close coupled argon-atomized alloy powder as the raw material. The optimal SPS parameters obtained using the L9(34) orthogonal test were 950 °C, 50 MPa and 15 min, and the relative density of the as-sintered alloy was 99.8%. The rapid densification of SPS effectively inhibited the growth of the Cr2Nb phase, and the atomized powder microstructure was maintained in the grains of the alloy matrix. Uniformly distributed multi-scale Cr2Nb phases with grain sizes of 0.10−0.40 μm and 20−100 nm and fine grains of alloy matrix with an average size of 3.79 μm were obtained. After heat treatment at 500 °C for 2 h, the room temperature tensile strength, electrical conductivity, and thermal conductivity of the sintered Cu−2Cr−1Nb alloy were 332 MPa, 86.7% (IACS), and 323.1 W/(m·K), respectively, and the high temperature tensile strength (700 °C) was 76 MPa.