Effect of Welding Parameters on Defects and Fracture Behavior of Friction Stir Welded 2195-T8 Al-Li Alloy Joints

Abstract:

In this work, the ratio of rotation rate to advancing speed was fixed to 10 to fabricate friction stir welding (FSW) butt joints of 2195 - T8 plates with 7.5 mm in thickness. The results revealed that the heat input of joints along the vertical direction varied with the welding parameters though these parameters had a same ratio. 500-50 and 600-60 joints failed in the thermal affected zone and thermal mechanical affected zone (TAZ/TMAZ), while other joints all failed in stirred zone (SZ). The hardness profile across the joints showed a similar W shape, while the hardness in bottom area increased with the increasing of parameters. Lazy S and kissing - bond defects appeared in all of these joints, and over - burn defect was also found in 1000-100 joint. It is concluded that the heat input distribution gradient during FSW across the joints becomes non-uniform and a sudden change between upper and lower areas even occurs.

• Periodical: Materials Science Forum (Volume 913)
• Pages: 182-189
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.913.182
• Online since: February 2018
• Authors: Yang Wu, Hua Mao, Qing Bo Yang, Zhi Qing Zhang*
• Keywords: 2195 Al-Li Alloy, Defect, Fracture Behavior, FSW, Welding Parameters

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