Characteristics of Microstructure and Microhardness of Friction Stir Welded Joints for AZ31 Magnesium Alloy

Abstract:

The joints of magnesium alloy plate with 4 mm thickness was successfully welded by friction stir welding, and the characteristics in microstructure and microhardness of joints after heat treatment were investigated. The results indicate that the tensile strength of as welded joint exceeds 220 MPa, nearly 83% strength of basic metals. During heat treatment, the grains in nugget zone grow gradually, while the grain recrystallization was occurred in heat affected zone and basic metal zone when the temperature is 150°C. As the temperature increases continuously, the grains will grow obviously. The average microhardness of joint will increase and reaches a maximum of 73 Hv at 250°C, and then will decrease sharply with increase of heat treatment temperature.

• Periodical: Applied Mechanics and Materials (Volume 472)
• Pages: 612-616
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.472.612
• Online since: January 2014
• Authors: Shan Lin Wang, Heng Yv Zhang, Xing Li
• Keywords: AZ31 Magnesium Alloy, Friction Stir Welding (FSW), Heat Treatment, Microstructure

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