Abstract
Harmonic-structured Cu–Sn alloys were produced via mechanical milling (MM) followed by spark plasma sintering (SPS), and their microstructure and mechanical properties were investigated. Microstructural observation of the MM powders and SPS compacts was achieved using scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The mechanical properties of the SPS compacts were evaluated using results of the tensile test and Vickers hardness test. SEM/EDS micrographs and XRD profile indicated that the harmonic-structured Cu–Sn alloy compacts have the network region with highly Sn solid solution, which is including some γ phase, and the dispersed region with pure Cu. The harmonic-structured Cu–Sn alloy compacts demonstrate the stabilized high strength, sufficient ductility and high hardness compared with the incomplete harmonic-structured Cu–Sn alloy in spite of the same addition of Sn. In the specimen after the tensile testing, many cracks were observed in only network region. This result indicates that advanced ductility of the harmonic-structured materials is attributed to the obstruction of the crack propagation by the dispersed region. The network structure in the harmonic-structured materials is effective for an improvement of the mechanical properties.
