Microstructure and crystallographic properties of Cu77Zn21 alloy under the effect of heat treatment

The influence of heat treatment process on microstructure and physiochemical properties of Cu77Zn21 alloy was studied. Samples were heated from 300 to 700 degrees C for 15 minutes and gradually cooled to room temperature. Samples were characterized using mechanical testing and surface analysis techniques. It was observed that the grain size increases with the increasing temperature. The decrease in hardness is due to composition change of the Cu-Zn alloy attributed to zinc diffusion.XRD shows the presence of only alpha brass with a preferential orientation along the (111) plane. The analyses show that temperature affects the crystalline parameters. The rms microstrain was reduced mainly by thermal activation. The heat treatment promotes atomic diffusion and leads to a better crystallinity of the particles. The results of Raman investigations confirmed the changes in the Cu-Zn alloy surface composition with a clear enrichment in CuO. This behavior correlates with the results obtained by mechanical testing.