Multi criteria decision making in the selection of machining parameters for Inconel 718

Abstract

Machining is a process of material removal using several cutting newlinetools and machine tools to accurately obtain the required product dimensions with good surface finish. In this research, attention is focused on the machinability assessment of nickel based alloy Inconel 718. Inconel 718 finds application in rotor blades, casing rings, aero engine parts, and automobile industries. The objective of this research focuses on Multi objective optimization of turning of Inconel 718, involving six objective functions newlinenamely minimization of surface roughness, tool wear, power consumption, cutting forces and maximization of tool life and material removal rate using Non-dominated Sorting Genetic Algorithm (NSGA-II) for machinability assessment of Inconel 718. Also this work focuses on Multi Criteria Decision Making (MCDM) model, which ranks the alternatives and the criterion which is given the highest rank is recommended as the best alternative to the decision maker. In this research work, six machining attributes are involved. The machining attributes are surface roughness, cutting forces, tool life, tool wear, power consumption and material removal rate. The machining parameter level is chosen within the intervals based on the recommendations by the cutting tool manufacturer. In full factorial design, three process parameters at three levels led to a total of 27 tests for machining processes. The use of a modified L27 orthogonal array, with three machining parameters, required only a limited newlinenumber of work pieces to conduct the experiments. The experiments have been conducted on the CNC lathe by varying the machining parameters such as cutting speed, feed and depth of cut. To investigate the machinability assessment of Inconel 718 involving six objective functions, single pass turning operation is carried out in dry condition.