Experimental investigation and numerical study on ultrasonic impact treatment of pure copper

Ultrasonic impact treatment (UIT) is a promising surface treatment technology and is widely used for the improvement of surface integrity of metallic materials. A double-axis mobile platform was built to experimentally investigate UIT of pure copper in terms of the resultant indentation profile, microhardness and microstructure. According to the experimental schematic, a macro-scale three-dimensional finite element model in conjunction with a physical-based constitutive model was developed to simulate the dynamic process of UIT of pure copper, the UIT-induced dynamic stresses and in-depth redistributions of time-related stresses were numerically studied, and the predicted indentation profile accords well with the experimentally measured result. In order to capture the features of grain refinement resulting from dynamic recrystallization, a calculation framework coupling the multi-scale finite element simulations with cellular automata scheme was proposed, which is significantly useful for optimization of UIT process parameters and quantitative investigation of UIT-induced grain refinement. •A double-axis mobile platform is built to experimentally investigate UIT of pure copper.•A macro-scale three-dimensional finite element model is established to simulate the dynamic process of UIT.•A constitutive model considering thermal activation, dislocation density evolution and dislocation drag effect is developed.•A calculation framework is proposed to capture the features of grain refinement resulting from dynamic recrystallization.•The microstructure observation of UITed pure copper is performed by EBSD.