ABSTRACT In the present study, 2195 aluminium–lithium (Al–Li) alloy joints were welded by laser-metal inert gas (laser-MIG) hybrid welding. The effect of different laser powers (700, 1000, and 1300 W) on the microstructures and mechanical properties of the weld joints was investigated. The dendritic solidification structure of the weld joint comprised the α-Al, θ-(Al2Cu), and T-(AlLiSi) phases. When the laser power increased, the grains coarsened, and the amount of the precipitated phase decreased. Consequently, the micro-hardness of the weld decreased. The heat input also increased with the increase in laser power. This increased the fluidity and solidification time of the liquid metal at the bottom of the molten pool. Therefore, the deposition of the particles of the refractory metal compounds and the formation of the equiaxed grain zone (EQZ) was hindered.

中文翻译：

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激光功率对2195铝锂合金激光-MIG复合焊接接头组织和力学性能的影响

摘要 在本研究中，2195 铝锂 (Al-Li) 合金接头通过激光金属惰性气体 (激光-MIG) 混合焊焊接。研究了不同激光功率（700、1000 和 1300 W）对焊缝显微组织和机械性能的影响。焊接接头的枝晶凝固组织包括α-Al、θ-(Al2Cu)和T-(AlLiSi)相。当激光功率增加时，晶粒粗化，析出相量减少。因此，焊缝的显微硬度降低。热输入也随着激光功率的增加而增加。这增加了熔池底部液态金属的流动性和凝固时间。所以，