Influence of Ni, Fe and Co on the microstructure and properties of 75% Cu–25% Sn alloy in hot pressing

Abstract

Ni, Fe and Co were added in 75% Cu–25% Sn alloys respectively for improving its microstructures and properties and decreasing the large weight loss of specimens in the high hot pressing temperature. Densification and mechanical tests were performed, and structures were investigated by X-ray diffraction, energy dispersive spectroscopy and scanning electron microscopy. When the hot pressing temperature was more than 700 °C, there were few weight loss of specimens with Ni added, a few weight loss of specimens with Fe added, and the large weight loss of specimens with Co added. All the Ni was dissolved in the Cu and δ-phase. Few Fe was dissolved in the Cu and δ-phase and most of Fe formed a single-phase. A portion of Co was dissolved in the Cu and δ-phase while the rest formed a single-phase. The fracture of all the specimens was brittle. The wear resistance and TRS increased due to the solution strengthening of Ni.