Effect of cryo-rolling process on the microstructure,texture evolution,and wear behavior of Al-4.5%Cu alloy

Abstract

This study investigates the influence of cryo-rolling at 77 K on the microstructure and wear characteristics of Al-4.5%Cu alloys. This work is motivated by the need to enhance the microstructural stability and wear resistance of Al-4.5%Cu alloys for use in demanding engineering environments. The main aim of the present study is to evaluate the effectiveness of cryo-rolling in addressing the challenges of poor wear resistance and coarse grain structures commonly found in conventional Al-4.5%Cu alloys. Electron backscatter diffraction (EBSD) analysis revealed a substantial grain refinement, with the average grain size decreasing from 81 µm in the base alloy to 6.4 µm after cryo-rolling. Additionally, the proportion of high-angle grain boundaries increased significantly from 4% to 55%, while low-angle boundaries decreased from 96% to 45%. Texture analysis indicated a transition from the base alloy’s rolling texture to dominant copper and brass texture components in the cryo-rolled alloy, suggesting enhanced deformation behavior. Wear testing over a sliding distance of 1200 m showed a marked reduction in wear rate—from 0.00925 mg/m in the base alloy to 0.00725 mg/m in the cryo-rolled alloy—indicating improved wear resistance. SEM observations further supported these findings, which revealed smoother worn surfaces with fewer pits and grooves in the cryo-rolled samples. Overall, the study confirms that cryo-rolling at 77 K significantly improves the microstructural features and tribological performance of Al-4.5%Cu alloys.