Experimental study on surface residual stress and hardness of rotary ultrasonic grinding of titanium matrix composites

Abstract

Abstract TiBw mesh reinforced titanium matrix composites were investigated by rotary ultrasonic grinding experiments using nickel-based electroformed diamond grinding wheel and building a single diamond abrasive grain model and a 2D rotary ultrasonic grinding finite element model. Surface residual stress is obtained by simulation and verified by univariate experiments. Combined with nanoindentation experiments, the changes of residual stress and hardness were acquired. The results show that the reinforced phase fibers will be subjected to high mechanical stress which break the fibers and turn into chips with matrix material. The residual stress of TiBw-rich region is closer to the actual value due to the high elastic modulus and low residual strain of TiB. Residual compressive stress around − 500MPa exists in the surface of workpiece under different process parameters. As the grinding depth increases, the residual stress increases first and then decrease. At the same time, the residual stress increases as the feed speed increase. And the residual stress decreases remarkably as the spindle speed increases. Meanwhile, the work hardening of workpieces changes similarly as the residual stress. The error between experiment and simulation is under 10%, which verified the effectiveness of the finite element model.