Enhanced Long-Term Reliability of Seal DeltaSpot Welded Dissimilar Joint between 6061 Aluminum Alloy and Galvannealed Steel via Excimer Laser Irradiation

Materials

Dong Jin Yoo¹  Min-Suk Oh¹  Sung-Min Joo²  Chang-U Jeong³  Jeshin Park³  Young-Gon Kim⁴  Young-Jin Kwak⁵ 

[1] Department of Energy Storage/Conversion Engineering of Graduate School, Jeonbuk National University, Jeonju 54896, Korea;Department of Naval Architecture and Ocean Engineering, Chosun University, Gwangju 61452, Korea;Division of Advanced Materials Engineering and Research Center for Advanced Materials Development, Jeonbuk National University, Jeonju 54896, Korea;EV Component & Materials R&D Group, Korea Institute of Industrial Technology (KITECH), Gwangju 61012, Korea;POSCO Technical Research Laboratories, Gwangyang 545875, Korea;

关键词: dissimilar joint;    galvanic corrosion;    adhesive bonding;    excimer laser irradiation;   

DOI  :  10.3390/ma14226756

来源: DOAJ

【 摘 要 】

Structural-adhesive-assisted DeltaSpot welding was used to improve the weldability and mechanical properties of dissimilar joints between 6061 aluminum alloy and galvannealed HSLA steel. Evaluation of the spot-weld-bonded surfaces from lap shear tests after long-term exposure to chloride and a humid atmosphere (5% NaCl, 35 °C) indicated that the long-term mechanical reliability of the dissimilar weld in a corrosive environment depends strongly on the adhesive–Al6061 alloy bond strength. Corrosive electrolyte infiltrated the epoxy-based adhesive/Al alloy interface, disrupting the chemical interactions and decreasing the adhesion via anodic undercutting of the Al alloy. Due to localized electrochemical galvanic reactions, the surrounding nugget matrix suffered accelerated anodic dissolution, resulting in an Al6061-T6 alloy plate with degraded adhesive strength and mechanical properties. KrF excimer laser irradiation of the Al alloy before adhesive bonding removed the weakly bonded native oxidic overlayers and altered the substrate topography. This afforded a low electrolyte permeability and prevented adhesive delamination, thereby enhancing the long-term stability of the chemical interactions between the adhesive and Al alloy substrate. The results demonstrate the application of excimer laser irradiation as a simple and environmentally friendly processing technology for robust adhesion and reliable bonding between 6061 aluminum alloy and galvannealed steel.

【 授权许可】

Unknown