Optimization of process parameters to minimize the wear loss of Al7075 T6/B4C composites developed by stir casting process

Abstract

This study investigates the dry sliding wear behaviour of Al7075-T6 matrix composites reinforced with various weight percentages (8–16 wt. %) of nano-sized boron carbide particles. The composites were fabricated using the stir-casting technique. Wear tests were carried out using a pin-on-disc tribometer. The process parameters considered were load (10–50 N), sliding speed (1.5–3.5 m/s), and sliding distance (800–1200 m), and these were optimized using the Taguchi method. The results showed that the highest wear loss of 3.146 mm³/km occurred at 8 wt. % B₄C, while the lowest wear loss of 1.203 mm³/km was observed at 16 wt. % B₄C under optimal conditions. Hardness increased by 11.08% as the reinforcement level rose from 8 wt. % to 16 wt. %, and the ultimate tensile strength improved by 2.88%. Regression modelling exibited high predictive accuracy (R² = 95.92%). The optimal combination of parameters was 16 wt. % B₄C, 10 N load, 1.5 m/s sliding speed, and 800 m sliding distance, which resulted in the minimum wear loss, with validation showing only 1.23% error. These composites are suitable for demanding applications where high wear resistance is essential, such as automotive brake rotors, aerospace bushings, and military structural components.