Performance Optimization on Squeeze Casting Process Parameters of AA7075 Based Composites for Corrosive Environment

Aluminium Hybrid Metal-Matrix Composites (AHMMCs) are advanced materials used in lightweight, high-strength applications, notably in aerospace and automotive industries. This study utilized AA7075 for its strength and ductility, improving its wear and corrosion resistance by reinforcing it with 12 wt.% titanium carbide (TiC) and varying amounts (2-6 wt.%) of boron nitride (BN) using squeeze casting. Process parameters-melting temperature, squeeze pressure, and period of stirring are optimized using Design Matrix of L9 and Grey Relational Method (GRM), with 750°C, 100 MPa, 15 minutes, and 4 wt.% BN identified as optimal. SEM analysis confirmed uniform BN distribution up to 4 wt.%, while 6 wt.% led to agglomeration due to weak wetting and high surface-energy. Mechanical and corrosion properties were significantly improved with 4 wt.% BN, including increases in microhardness (68%), tensile strength (29.6%), compressive strength (29.5%), impact strength (87%), wear resistance (69%), and corrosion resistance (64.5%) compared to unreinforced AA7075. These enhancements are attributed to refined microstructure, better load transfer, and improved resistance to dislocation and surface degradation. The study confirms the potential of BN and TiC-reinforced AA7075 composites for high-performance engineering applications.