Estimation of Optimal Laser Parameters On Inconel 718 By Taguchi Methodology

Abstract

Inconel 718 is a representative of high temperature alloy which poses substantial difficulties in machining processes. High strength, high cutting temperature and a subsequent work hardening during machining process adversely affect the cutting force, surface integrity, tool life and chip breakability. The above difficulties have been disproving by employing the Laser Assisted Machining (LAM). LAM is a hybrid technique and used to machining the work-piece with conventional tool after softening it with laser emitted heat. An attempt has been made in the present study for an experimental investigation on the machining attributes of 718 Inconel super alloy during laser assisted machining using uncoated carbide insert. Experimental plan is designed based on Taguchi’s L18 mixed orthogonal array of design of experiment. Three response values such as cutting force, surface roughness and tool wear are measured and their effects are studied. The variability due to the machining parameters are dispensed using variance test. Predictive regression equations are developed for the estimation of all the quality characteristics. Also the Pearson correlation coefficient analysis is calculated to analyze the correlation between the input parameters and quality characteristics. Results showed a strong correlation between the feed rate and the cutting force and surface roughness followed by cutting speed. The results obtained from experiments are analyzed to predict the optimal machining conditions using desirability approach. At the optimal laser parameters, the tool life, when laser beam is used, is improved by 9% compared to conventional machining.