Improvement of wear and corrosion resistance of aluminum alloy weld by constructing a laminate microstructure

Abstract

Periodic ultrasonic vibration enhances aluminum alloy weld surface properties by constructing a laminate microstructure, significantly improving wear and corrosion resistance. This study examined how periodic ultrasonic vibration influence laminate microstructure development, wear resistance, and corrosion resistance. The main results are as follows: The laminate weld microstructures with different layer widths could be designed by varying the switching-on/off time of the ultrasonic vibrations. The stratification features become less distinct when the switching-on/off time is short, as this leads to a reduced distance between layers. Weld microstructures with obvious delamination characteristics can be obtained when the switching-on/off time is 0.4 s and 0.7 s. Following the application of periodic ultrasonic vibration, a significant increase in both dislocation density within the weld grains and the number of subgrain boundaries was observed. The interfacial density and subgrain structure play a crucial role in determining the wear and corrosion resistance properties of weld. The application of ultrasonic vibration with a switching-on/off time of 0.1 s/0.1 s leads to significant improvements in weld performance, showing a 49.67 % reduction in wear rate and a 52.92 % decrease in corrosion current density compared to the original weld characteristics.