Optimisation of Cutting Parameters Using an Empirical Model to Achieve the Appropriate Surface Roughness of an O-Ring Groove

This study was conducted to investigate the effects of cutting parameters (cutting speed, feed rate, and depth of cut) on the average roughness (Ra) of an O-ring groove base by performing grooving experiments on titanium alloy (Ti6Al4V) using coated carbide tools and oil-based coolant. The experimental design is based on a central composite design template of response surface methodology. The results show that the relationship between the cutting parameters and average roughness is best represented by a quadratic model. ANOVA was employed to check the adequacy of the proposed model and the percentage contribution of significant factors to the development of the model. Feed was the most significant factor, with the largest contribution of 67.05%, followed by the quadratic and interaction terms. The results of the additional validation runs showed that the predicted roughness matched reasonably well the actual roughness, with an average prediction error of 15.8%. The contour plots and response surfaces developed in this study will help in selecting the optimum machine parameters for the desired roughness of the O-ring groove base.