MECHANICAL AND TRIBOLOGICAL STUDIES OF AA7075 METAL MATRIX COMPOSITES

Aluminum-based metal matrix nanocomposites (MMNCs) are gaining popularity in automotive aerospace and marine industries due to their lightweight high strength and excellent wear resistance. In this study AA 7075 alloy was used as the base material and reinforced with nano-sized aluminum oxide (Al₂O₃) silicon carbide (SiC) and a fixed amount of magnesium (1 wt.%) to improve wettability. These reinforcements were added in varying weight percentages (1%-4%) using the stir casting method which ensures uniform particle distribution and reduces porosity. Microstructural analysis confirmed a mostly uniform dispersion of particles while mechanical tests showed that the addition of reinforcements significantly improved hardness tensile strength and wear resistance although ductility slightly decreased. Hybrid composites (Al₂O₃ + SiC) performed better than those with single reinforcements. Overall the study demonstrates that stir-cast AA 7075 nanocomposites offer enhanced properties and are well-suited for high-performance engineering applications.