Effect of TiO 2 , BN, and WC Nano-Reinforcement on the Mechanical and Tribological Performance Al7075 Hybrid Composites

Lightweight alloys that can endure mechanical loading and resist wear are increasingly important in modern engineering. With this need in view, the present work examines how Al7075 responds when reinforced with a combination of TiO₂, BN, and WC nanoparticles. The composites were produced through an ultrasonic-assisted stir-casting process, where the stirring duration, melt temperature, and reinforcement levels (3%, 6%, and 9%) were varied in a planned manner using a DOE approach. Nine different compositions were cast and later tested for their tensile strength, hardness, wear behaviour, and microstructural features as per standard procedures. The experimental results show that the addition of these nanoparticles offers a clear improvement over the base alloy. The sample containing 9% TiO₂ + BN displayed the highest hardness, while several other hybrid mixes also demonstrated better wear resistance, largely owing to improved bonding between the matrix and the particles. SEM examination supported these findings by showing a reasonably uniform dispersion of particles and fracture surfaces that reflected both ductile and brittle modes. The outcomes of the study indicate that combining TiO₂, BN, and WC provides a practical way to enhance the mechanical and tribological performance of Al7075, making the developed composites suitable for structural applications.