Effect of ultrasonic vibration extrusion cutting on the corrosion resistance of ultra-fine grained strips

Abstract

Ultrasonic vibration extrusion cutting (UVEC), a new processing method, is proposed to prepare ultra-fine grained materials with better corrosion resistance. The mathematical models, finite element simulations, and experiments are combined and validated against each other to investigate the mapping relationships and influence mechanisms among ultrasonic amplitude, stress field parameters, microstructure, and corrosion resistance. It is found that with the increase of ultrasonic amplitude, the equivalent strain, equivalent strain rate, grain refinement degree of strip and thickness of a nanocrystalline surface layer on the side of the strip in contact with a tool (front side) increase gradually. The immersion corrosion test shows that both sides of the strip have better corrosion resistance than original matrix, and the corrosion resistance of the strip front side is better than that of strip side in contact with the extrusion block (back side). The electrochemical corrosion test shows that with the increase of ultrasonic amplitude, the electrochemical parameters are improved. It is determined that the corrosion resistance of ultra-fine grained strips prepared by UVEC is significantly improved compared with the original matrix, and the overall corrosion resistance is best at 2 μm ultrasonic amplitude.