A study on performance characteristics and multi response optimization of process parameters to maximize performance of micro milling for Ti-6Al-4V

Abstract

In machining of hard metals, surface roughness, tool vibration and tool wear are used as performance characteristics to estimate overall performance of process. This work is aimed to maximize overall performance in micromachining of Ti-6Al-4V and investigate effect of process parameters on performance characteristics. As per orthogonal array of L27, twenty seven experiments are carried out on the proposed metal with cemented carbide tools at three levels of cutting speed, feed and depth of cuts. According to user's preference rating, graph theory and matrix approach is used to estimate weights and preference scales for the performance characteristics. Utility concept is used to calculate overall performance of the process using weights and preference scales. Responses surface methodology is used to optimize process parameters to maximize overall performance of the process. In this study, maximum performance of the process is found at cutting speed of 19.78 m/min, feed of 75 μm/tooth and depth of cut of 50 μm. In addition to that, metal recovery in machining due to elastic recovery is also estimated theoretically and measured practically for different uncut chip thicknesses.