Investigation of melting rate in welding of IN738 Nickel-based superalloy by Nd:YAG pulsed-laser method

Abstract In this study, the effect of different parameters of pulsed Nd:YAG laser welding, including pulse energy, pulse frequency, pulse duration, and welding speed on the melting rate of IN738 Nickel-based superalloy, was investigated. The results of this study were obtained based on the modification of a formula for calculating the melting rate of welding by pulse method (pulse overlap). According to this formula, effective pulse energy (EPE) affected by pulse overlap, has a significant effect on the melting rate. So that by decreasing the amount of EPE (increasing the pulse overlap), the melting rate increases to 67% overlap and then decreases due to the reduction of the heating rate through heat transfer to the base metal. The study of the effect of pulse laser parameters showed that pulse energy, pulse overlap, and pulse duration have the greatest effect on melting rate, respectively.