Effects of process parameters in gas tungsten arc welding of thin titanium plates

This work systematically explores the effects of process parameters on the technological responses, including Tensile Force (TF) and the Average Micro-Hardness (AMH), in Gas Tungsten Arc Welding (GTAW) of titanium. Process parameters are welding current (I), gas flow rate (F), and arc gap (G). The objective of this work is to improve tensile strength with respect to micro-hardness constraints. GTAW welding machine was utilized with the Box-Behnken matrix to conduct experimental trails. The nonlinear relationships between welding parameters and responses were developed using Response Surface Method (RSM). Subsequently, an optimization technique, entitled Desirability Approach (DA), was used to analyze the trade-off among the considered responses and to find the optimal parameters. Conformity test was carried out in order to evaluate the accuracy of optimal values. The results showed that welding current had the greatest influence on the outputs among all factors. The measured improvements with optimal parameters of TF and AMH were approximately 4.10% and 6.12%, respectively, in comparison with the initial setting. The hybrid approach comprising RSM and DA was found an effective method for obtaining significantly optimal values in GTAW processes. © 2020 Sharif University of Technology. All rights reserved.