Numerical and Experimental Analysis of Surface Roughness of AISI D3 Alloy Steel during Pocket Milling Operation

—Surface roughness is a quality index which partly determines the ability of a material to meet its service or functional requirements. In this study, the Response Surface Methodology (RSM) was used for numerical analysis of the pocket milling operation of AISI D3 alloy steel and this was validated via physical experimentations. The physical experimentations were carried with the aid of a Deckel Maho DMU80mono BLOCK 5-axis CNC milling machine. The range of the process parameters selected include; feed rate between 0.1-0.5 mm/rev, depth of cut between 1- 3 mm and speed of cut between 150-375 m/min. The RSM generated 20 possible experimental runs while their responses (surface roughness) were gotten from physical experimentations. The results of the physical experimentations serve as input into the numerical analysis carried out using the RSM. This was used to obtain a predictive model equation for determining the magnitude of surface roughness as a function of the three cutting parameters employed (feed rate, depth of cut and cutting speed). Furthermore, the optimisation of the solutions obtained generated 10 possible solutions whose desirability values were equal to 1. The findings of this study may assist machinist in achieving good surface quality during the milling operation of AISI D3 alloy steel.