Investigation on machinability characterisation of Al7075-fly ash composite using Taguchi approach

In this research investigation, stir casting was used to fabricate metal matrix composites (MMCs) using (150 µm) fly ash particulates as reinforcement and Al7075 aluminium alloy as the matrix. Machining tests were performed on a CNC turning machine with cermet tool insert. The addition of fly ash improved tensile strength and hardness. Microstructural analysis shows a uniform dispersion of particles. The effects of process parameters on main cutting force, power consumption and surface roughness were investigated using a L9 orthogonal array and ANOVA. Main cutting force, power consumption and surface roughness were compared to cutting speed, feed rate and depth of cut. The results showed straight proportionality with cutting speed (100-180 m/min), feed rate (0.10-0.16 mm/rev), depth of cut (0.1-0.3 mm) and increased with reinforcement (2.5-7.5 wt. %). Microstructure, chip formation and tool wear were analysis using scanning electron microscopy.