Abstract In the present study, the microstructure and corrosion behaviour of laser beam welded 2A97 alloy are investigated. Welding process results in segregation of alloying elements within the fusion zone and, consequently, formation of T1 (Al2CuLi), TB (Al7Cu4Li) and R (Al5CuLi3) phase interdendritic intermetallics. The distribution of the interdendritic intermetallics is non-uniform across the weld. In NaCl solution, corrosion initiates at interdendritic intermetallic with selective dissolution of Al and Li, resulting in a copper-rich remnant, which subsequently acts as effective cathode supporting the dissolution of alloy matrix. The equiaxed dendrite zone at the centre of the weld is most susceptible to corrosion.

中文翻译：

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激光焊接引入偏析及其对铝铜锂合金腐蚀行为的影响

摘要 本研究对激光焊接2A97合金的组织和腐蚀行为进行了研究。焊接过程导致熔合区内合金元素的偏析，从而形成 T1 (Al2CuLi)、TB (Al7Cu4Li) 和 R (Al5CuLi3) 相间枝晶间金属间化合物。整个焊缝中枝晶间金属间化合物的分布是不均匀的。在 NaCl 溶液中，腐蚀从枝晶间金属间化合物开始，Al 和 Li 选择性溶解，产生富铜残余物，随后作为有效阴极支持合金基体的溶解。焊缝中心的等轴枝晶区最容易腐蚀。