Non-isothermal aging behavior of a friction-surfaced Al-Cu-Mg alloy matrix composite coating reinforced by nickel-aluminide

This study investigates the effect of nickel-aluminide on Al-Cu-Mg alloys’ non-isothermal aging behavior. The microstructure, mechanical properties, and corrosion resistance of nickel-aluminide-containing Al-Cu-Mg alloys were evaluated after non-isothermal aging treatment. The results show that the presence of nickel aluminide in the Al-Cu-Mg alloy changes the nature of S-Al 2 CuMg precipitates to θ -Al 2 Cu precipitates by adding 1.5 wt% Ni to the Al-Cu-Mg matrix. The non-isothermal aging treatment temperature for achieving the maximum mechanical properties during non-isothermal aging shifted from 250 °C to 300 °C. Compared to isothermal artificial aging treatment at 170 °C, the maximum hardness and mechanical properties increased by up to 9% in a nickel-aluminide containing Al-Cu-Mg alloy after non-isothermal aging treatment. The nickel-aluminide containing sample’s maximum hardness and shear strength is HV 0.1 (143.4±6.4) and (298.6±9.6) MPa, respectively occurring at 300 °C. After non-isothermal aging treatment, the corrosion current intensity was reduced by approximately 58% and 49% in the nickel-containing coating compared to the AA2024 aluminum alloy substrate and coating without nickel-aluminide, respectively. Compared with the conventional artificial aging treatment, the corrosion current decreased by 16.7% more after non-isothermal aging treatment in the nickel-aluminide-containing coating.