Optimization of drilling parameters for Al6061/Al6063–SiC–ZrO2 composites using TOPSIS considering microstructure and machinability

The increasing demand for lightweight, high-strength components in aerospace, automotive, and electronics has intensified interest in aluminium matrix composites (AMCs) with enhanced machinability. Drilling of particle-reinforced AMCs remains challenging due to burr formation and surface quality issues. In this study, Al6061 and Al6063 alloys reinforced with 3 wt.% SiC and 2 wt.% ZrO₂ were fabricated via stir casting to achieve uniform particle dispersion. Drilling experiments evaluated the influence of spindle speed and feed rate on drilling time, burr formation, and surface roughness. Microstructural analysis (SEM/EDS) confirmed homogeneous reinforcement distribution with reduced clustering. Results revealed that increasing the spindle speed to 4540 rpm with a feed rate of 0.076 mm/rev reduced drilling time by 96% (Al6061) and 90% (Al6063), and improved surface finish by 32% and 55%, though burr heights increased significantly. TOPSIS identified 4540 rpm with 0.076 mm/rev as optimal, offering effective balance and applicable to precision AMC components.