Enhancing the Mechanical and Tribological Properties of Al-Si-Cu-Ni-Based Cast Al Alloy through Minor Zirconium Addition

Abstract

In the current study, attempts were made to enhance the mechanical (tensile, hardness) and tribological properties (room temperature and elevated temperature fretting wear performance) by minor Zr addition through the liquid metallurgy route. Al-Si-Ni-Cu-Zr base alloys with different Zr content (0, 0.2, and 0.4 wt.% Zr) were cast using a vacuum arc melting-cum casting unit. As-casted samples were subjected to solution treatment and aging (STA) heat treatment. The results showed that the STA alloy with 0.2 wt.% Zr showed significant improvement in ultimate tensile strength (309 ± 7.5 MPa) by 28.7 %, hardness (168 ± 3.2 H.V0.2) by 25 %, and room temperature fretting wear resistance (35.08 mm−3) by 38%, elevated temperature fretting wear resistance (40.81 mm−3) by 46 %, respectively, as compared to the base alloy (alloy without Zr content). Also, STA alloy with 0.2 wt.% Zr showed stability in microstructure and mechanical properties even after exposure to a higher temperature (200 °C) for a longer time. © 2022, ASM International.