Corrosion Resistance of MB8 Magnesium Alloy after Ultrasonic Impact Treating

Abstract. MB8 magnesium alloy was treated by using HJ-III type ultrasonic impact treatment machine. The effect of ultrasonic impact treatment parameters on the microstructure, residual stress in the surface and corrosion resistance was investigated. The test results indicate that the grain in the treated area was refined and residual compressive stress in the treated surface was formed. The thickness of the plastic deformation layer is about 260µm.The corrosion resistance was increased to a different degree. When the ultrasonic impact treatment current was 1.2A, the impact time was 6min, comparing to the untreated specimen, the corrosion resistance of treated specimen has been increased by 51.25%. The main reason for promote the corrosion resistance is grain refining and residual compressive stress which induced by ultrasonic impact treatment