A comparative study on microstructure, mechanical properties and pitting corrosion of gas tungsten arc, electron beam and friction stir welds of AA2219-T87 Al-alloy

• Main Authors: Prakash, K., Saranya, B. Lakshmi, SrinivasaRao, K., Reddy, G. Madhusudhan
• Format: Conference Proceeding
• Language: English
• Subjects: Aluminum base alloys; Base metal; Comparative studies; Construction materials; Corrosion potential; Corrosion resistance; Electron beam welding; Friction stir welding; Fuel tanks; Fusion welding; Gas tungsten arc welding; Mechanical properties; Microstructure; Optical microscopy; Pitting (corrosion); Pitting potential; Potential gradient; Strength to weight ratio; Tensile tests; Welded joints
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0068210

On account of high weldability and superior strength to weight ratio, the AA2219-T87 Aluminium-Copper alloy is recommended as a construction material of cryogenic fuel tanks. Though the corrosion resistance and mechanical properties of base metal are high, welded joints show low mechanical properties and corrosion resistance. In view of the above problem, attempts are made in the present study to analyze microstructural changes during welding processes and its affects on mechanical properties and pitting behavior of AA2219-T87 alloy. Gas Tungsten Arc welding, Electron Beam Welding and Friction Stir welding were employed in the present study. Microstructural changes in various zones of welds were studied using Optical Microscopy. The pitting corrosion behavior of base metal and welds were studied using potentiodynamic polarization testing. In accordance with hardness and tensile testing, mechanical properties were analyzed. The study confirmed that the mechanical properties and corrosion resistance are strongly dependent on the microstructural changes that occur in welds. It was found that friction stir welds’ mechanical properties are superior compared to GTA and EB welds. Pitting potential gradient across the various zones that form during welding was found to be much lower for friction stir welds of AA2219-T87 alloy compared to fusion welds of GTAW and EBW.