Effect of electropulsing treatment on the microstructure and superelasticity of TiNi alloy

Cold-rolled TiNi alloy was treated by electropulsing with different process parameters. The superelasticity, electrical resistivity and microstructure evolution of the TiNi alloy were investigated. The recrystallization is found to happen in the cold-rolled TiNi alloys during electropulsing treatment (EPT) processing and it took 9 s to complete the crystallization in the EPT process. In addition, the grain size increases with the charge voltage and the discharge frequency of the electropulse. The maximum superelasticity of 6.94 % is gained when the TiNi alloy is treated by the electropulsing with the frequency of 300 Hz. The short recrystallization time of the alloy is attributed to the acceleration of atomic diffusion and the movement velocity of the grain boundary by electropulsing. This research provides an in-depth understanding of how the electropulsing affects the microstructure and superelasticity of TiNi alloy.