Optimization of Processing Parameters During Laser Cladding of ZE41A-T5 Magnesium Alloy Castings Using Taguchi Method

A continuous wave 4 kW Nd:YAG laser welding system was employed to clad single beads on machined 6.2-mm thick ZE41A-T5 aerospace magnesium alloy sand castings using nominal 1.6-mm filler rods of the parent metal. Based on the quality criterion of minimum dilution ratio, the Taguchi experimental method was used to optimize different process parameters and to identify the dominating factors. It was found that, for the process window investigated in this work, the optimal levels were 5.0 m/min for wire feed rate, 2.25 kW for laser power, and 2.5 m/min for cladding speed, with a minimum dilution ratio of 0.155. With 95% confidence, the wire feed rate is the dominating factor with the most significant influence on the dilution ratio. The dilution ratio usually decreases with increased wire feed rate while it increases with increased laser power. By contrast, the cladding speed appears to have insignificant influence on the dilution ratio over the cladding speed range used in this study.