LAUSR

ABSTRACT In this study, the Al7075 alloy underwent modifications in its primary alloying components (Cu, Mg, Cr, and Zn) and incorporated a unique additive, SiC, to investigate their collective impact on mechanical, microstructural, and machining behavior. The goal was to enhance load-bearing and machining properties of the commercial Al-7075 alloy. Employing the stir casting process, the alloy was modified with varying weight percentages of Cu (1.2–4.8%), Mg (2.1–2.9%), Cr (0.18–0.28%), and Zn (5.1–6.1%) using an L8 orthogonal array. SiC was then added at 2%, 4%, and 8 wt% to the optimized composition. Results indicated that the composite with 4.8% Cu, 2.9% Mg, 0.18% Cr, and 5.1% Zn (Al7) exhibited maximum tensile strength and hardness. Al1 alloy displayed the highest energy absorption at 2.1J. Al7 alloy demonstrated superior wear resistance but with a higher wear rate of 0.320 mm3/min and a COF of 0.58. Microstructural analysis revealed finer grains and increased grain boundaries. The addition of SiC significantly enhanced tensile strength, hardness, impact toughness, and wear resistance as 223.56MPa, 118.6BHN, 1.14J and 0.127 mm3/Nm respectively, making it suitable for applications in industries such as aircraft, automotive, and defense where precise weight is crucial.