Influence of Electropulsing Treatment on Microstructure Evolution and Properties of ZK60 Alloy Sheets

Rolled ZK60 magnesium alloy sheets were processed by electropulsing treatment or equivalent heat treatment. Then, the microstructure evolution of the rolled sheets was investigated by optical microscope (OM) and electron backscattered diffraction (EBSD). The properties were also evaluated by tensile testing at room temperature. Results show that complete recrystallization occurs in a short time when the deformed ZK60 sheets are treated by electropulsing. The average size of recrystallized grains can reach 3 mu m, the tensile strength increases to 310 MPa, and the elongation is up to 30.7%. However, the incomplete recrystallization occurs in rolled ZK60 alloy which is treated by equivalent heat treatment with the same processing time. Therefore, the electropulsing increases the nucleation rate of recrystallization for the rolled ZK60 alloy and then accelerates the process of recrystallization. The electropulsing treatment optimizes the microstructure of the ZK60 alloy, resulting in high comprehensive mechanical properties.