Investigation on Microstructure Evolution of Hot Deformed Free-Cutting Cu-Zn-Se-Bi-Sn Alloy

The microstructure evolution of hot deformed Cu-Zn-Se-Bi-Sn alloy was investigated by Hitachi-800 transmission electron microscopy (TEM). The result shows that there are three different dislocation configurations such as dislocation network, dislocation wall and dislocation cell in hot deformed Cu-Zn-Se-Bi-Sn alloy. The dislocation network was firstly formed in some certain grains of Cu-Zn-Se-Bi-Sn alloy when the deformation strain amounted to 2%. Then dislocations initially arranged regularly beside original grain boundaries and the arranged dislocation walls were formed in some area and sub-grains merging emerged when the deformation strain amounted to 20%. Eventually, obvious dynamic recrystallization nucleation by sub-grain merging emerged in Cu-Zn-Se-Bi-Sn alloy when the strain attached 80%.