Development of Theoretical and Numerical Framework for Selecting the Cutting Process Parameters for Turned Slender Parts

Abstract

Metal cutting productivity or material removal rate is a constrained objective. Higher productivity, which is guaranteed by higher cutting process parameters (feed, speed, and depth of cut), is accompanied by higher constraining and unwanted factors like higher cutting forces, higher power demand, higher machine tool and workpiece deflections (in other words, form error), higher waste heat generation and coolant demand, faster tool wear rate, higher predisposition to periodic and regenerative chatter, compromised surface quality, etc. The research focused on the development of theoretical and numerical framework for selecting the cutting process parameters to enhance the productivity, integrity, and accuracy of turned slender parts. The method involved theoretical modelling that expresses material removal rate and form error in terms of cutting process parameters, workpiece flexibility parameters, workpiece geometrical parameters, and kinematic parameters. Cutting tests were carried out in validation of the arising theoretical and numerical results. Parametric studies were carried out using the developed computational model to understand the trend of accuracy and productivity with variation of cutting process parameter. As expected, the parametric study shows that flexibility of the slender workpiece reduced MRR. The results showed that deviation of predicted values of MRR from the desired values rises with rise of all the cutting process parameters; feed, depth of cut and spindle speed. The findings also indicate that as the feed rate and depth of cut increase, the variance between the predicted diameter and the target values also increases. However, there is a fluctuating pattern with a gradual decrease in variance as the spindle speed rises. Based on the results of the parametric studies, specified tolerance ranges could be met by choosing parameter sets that meet the specifications. If the numerical model relies on FEA, it might require extensive computational resources and expertise, limiting its practicality. Overcoming these limitations often involves continuous research and development efforts, incorporating real-world data, and improving the accuracy and adaptability of the framework for specific machining scenarios. The parametric study results can be used as a framework for the selection of cutting process parameter to enhance the productivity, integrity, and accuracy of turned slender parts.