Effect of Laser Power on Corrosion Properties of Hybrid Welded 2195 Al-Li Alloy

In this work, the effect of laser power on corrosion properties of 2195 Al-Li alloy laser hybrid welded joints was investigated. The results show that with the laser power increases, the microstructure of the weld is coarsened, the amount of bright white and dark black precipitates decrease, the size of the precipitates increases and the distribution is nonuniform. Electrochemical test shows that the corrosion resistance of the base metal (BM) is lower than that of the heat-affected zone (HAZ), and the corrosion resistance of the weld is the highest among the areas considered herein. The corrosion resistance of the weld increases with increasing laser power. The result of inter-granular corrosion (IGC) testing shows that the HAZ has the best IGC resistance among the areas considered herein. The IGC analysis of the weld metals shows that the average and maximum depth of IGC decrease with increasing laser power. When the laser power reaches 1300 W, the average and maximum depths of inter-granular corrosion are 146 μm and 164 μm, respectively.