Optimisation of machining parameters in laser aided hybrid machining of Inconel 718

This study focused on experimental investigation and optimisation of laser aided hybrid machining of Inconel 718 alloy. Cutting speed, feed rate and laser power are varied each at three levels and total of 27 experiments are conducted. Cutting force, surface roughness and flank wear are measured. The factor effects on each response are analysed using 3D surface plot. The developed regression model shows good degree of fit. From the analysis of variance, the feed rate and laser power are influencing parameters on the cutting force and surface roughness while cutting speed is for tool wear. The optimal process parameter setting using desirability analysis reveals a reduction of cutting force by 50%, surface roughness by 26%, flank wear by 33% and the tool life is extended up to 133% over conventional machining. The segmentation of saw tooth chip is increased which demonstrated the thermal softening effect compared to conventional machining.