Taguchi Optimization of Pulsed Current GTA Welding Parameters for Improved Corrosion Resistance of 5083 Aluminum Welds

• Published in: Journal of materials engineering and performance 2013-04, Vol.22 (4), p.1149-1160
• Main Authors: Rastkerdar, E., Shamanian, M., Saatchi, A.
• Format: Article
• Language: English
• Subjects: Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion; Corrosion and Coatings; Corrosion mechanisms; Engineering Design; Exact sciences and technology; Joining, thermal cutting: metallurgical aspects; Materials Science; Metals. Metallurgy; Quality Control; Reliability; Safety and Risk; Tribology; Welding
• ISSN: 1059-9495; 1544-1024
• DOI: 10.1007/s11665-012-0346-5

In this study, the Taguchi method was used as a design of experiment (DOE) technique to optimize the pulsed current gas tungsten arc welding (GTAW) parameters for improved pitting corrosion resistance of AA5083-H18 aluminum alloy welds. A L9 (3 4 ) orthogonal array of the Taguchi design was used, which involves nine experiments for four parameters: peak current ( P ), base current ( B ), percent pulse-on time ( T ), and pulse frequency ( F ) with three levels was used. Pitting corrosion resistance in 3.5 wt.% NaCl solution was evaluated by anodic polarization tests at room temperature and calculating the width of the passive region (∆ E pit ). Analysis of variance (ANOVA) was performed on the measured data and S / N (signal to noise) ratios. The “bigger is better” was selected as the quality characteristic (QC). The optimum conditions were found as 170 A, 85 A, 40%, and 6 Hz for P , B , T , and F factors, respectively. The study showed that the percent pulse-on time has the highest influence on the pitting corrosion resistance (50.48%) followed by pulse frequency (28.62%), peak current (11.05%) and base current (9.86%). The range of optimum ∆ E pit at optimum conditions with a confidence level of 90% was predicted to be between 174.81 and 177.74 mV SCE . Under optimum conditions, the confirmation test was carried out, and the experimental value of ∆ E pit of 176 mV SCE was in agreement with the predicted value from the Taguchi model. In this regard, the model can be effectively used to predict the ∆ E pit of pulsed current gas tungsten arc welded joints.