Comparative review and experimental validation of Tribological and Mechanical Properties of Zinc Aluminium Alloy (ZA27) and Aluminium Zinc Alloy (Al-25Zn)

Abstract

This paper offers a comprehensive review and experimental investigation into Zinc-Aluminum (ZA) and Aluminum-Zinc alloys, focusing on their mechanical and tribological properties. Zinc-based alloys like ZA27, ZA12, and ZA8 are esteemed for their superior bearing qualities, with ZA27specifically noted for its strength and widespread use in wear-resistant applications such as plain bearings and bushings. Despite surpassing materials like brass, bronze, and steel bearings, ZA alloys are constrained by their operational temperature limits above 100°C and exhibit lower ductility and impact resistance, potentially leading to dimensional instability. Enhancements via alloying elements (Cu, Mn, Mg, Ni, Si, Ti, Zr, Sr, Sc, Eu, Ag), heat treatment, and increasing aluminum content are identified strategies. The literature indicates that Al-25Zn has mechanical and tribological properties comparable to ZA27, although direct comparative experimental data are scarce. In this experimental investigation, aluminum, zinc, ZA27, and Al-25Zn alloys were fabricated using stir casting, and their properties were examined. Results show that the Al-25Zn alloy possesses the highest hardness, tensile strength, and wear resistance, as well as the lowest coefficient of friction (COF) among the materials tested. The Al-25Zn alloy offers higher elongation and similar thermal constraints, making it ideal for applications needing strong mechanical performance and low friction coefficients.