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

Abstract

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.