Metallurgical, mechanical and corrosion characteristics of vibration assisted gas metal arc AA6061-T6 welded joints

• Published in: Journal of advanced joining processes Vol. 6; p. 100129
• Main Authors: Ilman, M.N., Widodo, A., Triwibowo, N.A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2022; Elsevier
• Subjects: Aluminum alloy welding; Corrosion; Fatigue crack growth rate; In-process vibrational treatment; Strength; In-process vibrational treatment; Corrosion; Fatigue crack growth rate; Aluminum alloy welding; Strength
• ISSN: 2666-3309; 2666-3309
• DOI: 10.1016/j.jajp.2022.100129

•Vibration assisted welding (VAW) of AA6061-T6 has been studied.•VAW is performed at frequencies in the range of 0-500 Hz.•The best grain refinement is achieved at 300 Hz.•High strength of VAW joints is correlated with grain refinement.•VAW improves weld fatigue performance and corrosion resistance. Microstructure, mechanical properties and corrosion performance of gas metal arc AA6061-T6 aluminum alloy welded joints under the effect of mechanical vibration during welding have been investigated. The vibration frequencies, f used in this study were in the range of 0-500 Hz. Subsequently, several experiments were performed including microstructural observation, microhardness measurements, tensile tests, fatigue crack growth tests combined with fractography study and electrochemical polarization tests in 3.5% NaCl solution. Results indicated that the application of mechanical vibration increased tensile strength of the welded joints up to 83.3 % higher than the weld without vibration achieved at a frequency of 300 Hz. It was found that the strengthening mechanisms in the vibrated weld joints occurred mainly by the grain refinement of columnar dendritic and equiaxed dendritic microstructures in the weld metal region. Such microstructures could contribute to fatigue crack growth inhibition in the weld metal. Based on electrochemical corrosion tests, the vibration assisted weld joints were found to have better corrosion resistance than as-welded weld joint. The improved corrosion performance was likely attributable to suppression of intermetallic compound formation such as Mg2Si by mechanical vibration during weld solidification.