Influence of hot pressing temperature on the microstructure and mechanical properties of 75% Cu-25% Sn alloy

摘要

The alloy of 75% Cu-25% Sn was utilised and hot-pressed for 4 min at 421,520 and 600 ℃ to obtain a self-sharpening bond for diamond honing stones at low sintering temperature. Densification and mechanical tests were performed, and structures were investigated by X-ray diffraction, energy dispersive spectros-copy and scanning electron microscopy. Results showed that the porous structures changed into micro-porous structures when the hot pressing temperature was increased from 421 ℃ to 600 ℃. The mechanical properties improved from HRB 79.1 to HRB 105.1 in hardness and from 104.2 MPa to 201.4 MPa in transverse rupture strength. After hot pressing at 600 ℃, the microstructure consisted of α(Cu) + 8 eutectoid and micropores, which meets the requirements of bonds for honing stones.