Microstructure evolution and thermal expansion of Cu-Zn alloy after high pressure heat treatment

The thermal expansion coefficients of Cu-Zn alloy before and after high pressure treatment were measured by thermal expansion instrument in the temperature range of 25-700 °C, and the microstructure and phase transformation of the alloy were examined by optical microscope, X-ray diffractometer (XRD) and differential scanning calorimeter (DSC). Based on the experimental results, the effects of high pressure treatment on the microstructure and thermal expansion of Cu-Zn alloy were investigated. The results show that the high pressure treatment can refine the grain and increase the thermal expansion coefficient of the Cu-Zn alloy, resulting in that the thermal expansion coefficient exhibits a high peak value on the α-T curve, and the peak value decreases with increasing the pressure.