Microstructure of the pure copper produced by upsetting with ultrasonic vibration

The propagation of the ultrasonic wave in the solids can greatly affect the microstructure of the material. In this paper, upsetting with ultrasonic vibration as a novel method to produce the ultrafine grained material was presented to refine the pure copper grains. For the ultrasonic vibration upsetting, during the upsetting process, the ultrasonic wave propagates in the specimen at the same time. Under the coupling action of the ultrasonic and plastic deformation, the pure copper grains with the initial grain size of ~ 50 μm? were refined to about 100–300 nm after one time forming process. By comparing the ultrasonic vibration upsetting with the conventional upsetting process, the role that the ultrasonic wave played during the upsetting process was revealed.

► Ultrasonic vibration and plastic deformation are combined together to refine grains.
► Ultrasonic wave can greatly improve the grain refinement efficiency.
► Copper grains with size of 100~300 nm are obtained after one time forming process.