THE EFFECT OF SUPERIMPOSED LOW-FREQUENCY VIBRATION ON TENSILE DEFORMATION OF LOW-CARBON STEEL

It is well known that ultrasonic vibration can lead to significant load reduction in metal forming which is called acoustic softening and this phenomenon has been widely used in micro/meso forming. Recently, we found low-frequency mechanical vibration with micro-amplitude also had the same effect. Compared with the ultrasonic vibration, mechanical vibration is easier to obtain large force. In this study, tensile deformation of low-carbon steel assisted by low-frequency mechanical vibration with different amplitudes and the contributing mechanisms were investigated. The effects of mechanical vibration decreasing forming stress were analyzed and discussed. In addition, a modeling framework for the vibration plasticity was proposed based on the thermal activation theory. Results show that the reduction of the stress is proportional to vibration amplitude, and the deformed materials appear to permanent softening due to mechanical vibration. The findings of this study confirmed the significant effects of mechanical vibration on metal forming and provide a basis to understanding to vibration-assisted forming.