Optimization of Process Parameters of Plasma Arc Cutting Using Taguchi’s Robust Design Methodology

Abstract

One of the most important nonconventional machining methods is Plasma Arc Machining. Its high accuracy, high finishing, ability of machining any hard materials and to produce intricate shapes increased its demand in the market. It is cheaper than Laser cutting and about ten times faster than Oxy-fuel Cutting and hence is a better option for cutting many jobs. In this work the process parameters that influence the quality of cut in terms of the bevel angle have been analyzed statistically for cutting Mild Steel E350 grade sheets. The Current, Cutting Speed and Arc Gap have been considered as the important parameters. Taguchi Design of Experiments was used and analysis was done by Minitab 17 software. After performing Analysis of Means (ANOM), the optimum parameters have been found, percentage contributions of the parameters on the Bevel Angle have been obtained using Analysis of Variance (ANOVA), Regression equation being computed for the bevel angle and surface plot has been generated to understand the interactions of two factors on the Bevel Angle. From ANOVA it has been observed that the cutting speed influences the Bevel Angle the most with contribution of 62.18 % followed by arc gap with 15.16 % and the current 12.08 %.