Enhancement of tribological properties of AA7075 aluminum alloy using nano-silicon carbide reinforcement: A detailed wear analysis and microhardness study

Abstract

Aluminum is used in engineering materials to produce components with a higher strength-to-weight ratio. The tribological properties of the aluminum alloy AA7075MMC were improved by using nano-silicon carbide (SiC) with a particle of 50 nm size material as a reinforcement in various proportions (1%, 2 %, 3%, and 4% wt. of SiC) synthesized using liquid metallurgy stir-casting technique. A comprehensive wear analysis was performed using an advanced computerized wear tester, employing an EN-32 steel disc and a round pin as the nanocomposite sample. The wear rate was determined through the friction coefficient, weight loss, and specific wear rate calculations. The results demonstrate that the nano-enhanced composites exhibit superior wear resistance compared to the base alloy (Al 7075). High-resolution field emission scanning electron microscopy (HR FESEM) was employed to examine the structural and microstructural characteristics of the materials, as well as the wear surfaces and debris. The weight loss of the composites was observed, and the relationship between wear loss and applied load was investigated, revealing similar trends for both the reinforced composites and the metal matrix. Furthermore, the nanocomposites exhibited reduced wear rates compared to conventional metals. An increase in the weight percentage of SiC resulted in a decrease in the wear rate and friction coefficient, especially with higher sliding speeds and SiC weight fractions. FESEM analysis confirmed the presence of SiC and other phases in the composites. Notably, the 4 wt% SiC composite demonstrated significantly improved friction coefficient, wear rate, and weight loss compared to the Al 7075 matrix metal.