Optimization of Surface Roughness During High Speed Milling of Inconel 825 Using Grey Relation Analysis

Abstract

Inconel 825 is extensively used in harsh environment due to outstanding mechanical and chemical properties. However, Inconel 825 belongs to difficult to cut material due to the presence of hard carbide in microstructure that leads to poor machinability. In this context, this study experimentally investigated and optimized machining parameters during end milling using PVD TiAlN coated carbide tool to enhance surface quality and material removal rate. For this, three input variables such as cutting speed, feed per tooth and radial rake angle with three levels are used. L27 orthogonal array-based Taguchi’s design of experiments is used. Responses are analysed using statistical software MiniTab 2017. Grey relation analysis is used to convert multi-objective optimization into single response and is optimized using Taguchi method. It is observed that, during end milling of Inconel 825, the most optimal conditions are the cutting speed of 90 m/min, feed rate of 0.03 mm/rev and radial rake angle of 7°. Using the response table for mean, it was concluded that the feed rate has substantial influence on various performance characters over other milling parameters.