To evaluate the effect of impact energy on plastic deformation of metal

repeated impact tests of YT01 were performed on the cam mechanical multi touch machine in the laboratory. The plastic deformation of YT01 was investigated by Coordinate Grid method

while the microstructure and phase were investigated by scanning electron microscope (SEM) and metalloscope in order to understand the different impact energy on the plastic deformation and microstructure. The results show that: the cumulative plastic deformation was greater with increasing impact energy and unchanged impact stress. The plastic deformation rate decreased with the increase of the impact number. The plastic deformation stopped at 6-9 mm from the top surface. After 256 000 repeated impacts

microstructure refinement and increased grain boundaries occurred. Meanwhile

transgranular cracks and holes were presented at 6-9 mm from the contact surface due to intense shear deformation in the sample. As a consequence

the plastic deformation of metallic material is not only related with impact stress but also with impact energy.