Effects of Welding Wire Composition on Microstructure and Mechanical Properties of Welded Joint in Al-Mg-Si Alloy

Abstract:

The effects of welding wire composition on microstructure and mechanical properties of welded joint in Al-Mg-Si alloy were studied by electrochemical test, X-ray diffraction (XRD) analysis and metallographic analysis. The results show that the weld zone is composed of coarse columnar dendrites and fine equated grains. Recrystallized grains are observed in the fusion zone, and the microstructure in the heat affected zone is coarsened by welding heat. The hardness curve of welded joint is like W-shaped, the highest hardness point appears near the fusion zone, and the lowest hardness point is in the heat affected zone. The main second phases of welded joints are: matrix α-Al, Mg₂Si, AlMnSi, elemental Si and SiO₂. The addition of rare earth in welding wire can refine the grain in weld zone obviously, produce fine grain strengthening effect, and improve the electrochemical performance of weld.

• Periodical: Key Engineering Materials (Volume 905)
• Pages: 44-50
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.905.44
• Online since: January 2022
• Authors: Li Wang, Ya Ya Zheng*, Shi Hu Hu
• Keywords: Al-Mg-Si, Mechanical Properties, Welded Joint, Welding Wire

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