Experimental investigation on surface integrity of Inconel 718 under hot machining and optimisation of its process parameters

In the present paper, the Inconel alloy's heat-based machining has been conducted to analyse this influence on surface integrity. The pre-heating softens the workpiece, which indeed reduces the yield strength to make machining easier. However, the impact of pre-heating on residual stress required more focus, which indeed has an impact on fatigue life, so the experiments conducted with different cutting conditions such as speed, cutting tool, feed rate, and depth of cut with reducing of residual stress and surface roughness. The experimental results are compared with simulation results performed using ABAQUS/Explicit, which are acceptable. The optimal parameters determined using grey relational analysis (GRA) optimisation approach are TiN coated tool, speed 50 m/min, feed 0.11 mm/rev, depth of cut 0.3 mm, and pre-heating temperature 600 degrees C. From the obtained optimum parameters, the experiment has been carried out to validate the result. From ANOVA, it is identified that the pre-heating temperature is the top influential factor among all the factors.