The Effect of Electropulsing-Assisted Ultrasonic Surface Rolling Process on the Friction and Wear Properties of AA...

Aluminum alloy (AA) 2024-T3 is widely used in the aerospace industry due to its high specific strength and superior fatigue resistance, yet its moderate hardness and inadequate wear resistance fail to meet service demands under severe wear conditions. Although the electropulsing-assisted ultrasonic surface rolling process (EP-USRP) can strengthen its surface, the mechanism by which pulsed current density influences the friction and wear properties of the strengthened layer remains unclear. This study employed EP-USRP to strengthen the surface properties of AA 2024-T3, systematically examining the impacts of different pulsed current densities on its surface morphology, roughness, microhardness, and tribological performance, while comparing wear mechanisms among differently treated samples under various normal loads. The results indicate that EP-USRP can improve the surface mechanical properties compared with USRP. At 1.42 A/mm² current density, the EP-USRP-3 sample achieved 27.7% lower surface roughness and 19.6% higher microhardness. Under a 2 N normal load, its average friction coefficient, wear volume, and wear rate decreased by 5.34%, 36.28%, and 36.27%, respectively. Adhesive and oxidative wear, coupled with material spalling, constitute its main wear behavior. The electroplastic effect induced by pulsed current may facilitate the increase in strain levels and dislocation densities, which could contribute to the improved surface mechanical and tribological properties of AA 2024-T3.