Effect of laser power variation in AM-LMD process on Inconel 718 powder deposition profile on Inconel 738

The aim of this study was to investigate the effect of laser power variation on joint connection characteristics in the additive manufacturing (AM) process by depositing Inconel 718 powder on an Inconel 738 substrate in order to reconstruct defective gas turbine blades with a circular economy approach. Laser metal deposition (LMD) is a layer-by-layer fabrication technique used to manufacture and reconstruct critical and strategic parts. For this purpose, deposition with different power of 150, 250 and 350 watts was performed on the substrate. Some features such as geometric dimensions, number of pulses per layer and microstructure of the samples were studied. Comparing the results, it was found that with increasing strength, integrity, joint connection thickness and substrate melting depth increase. In contrast, with increasing power, surface porosity, and size deviation from the design dimensions, and the number of pulses to complete each layer decrease. Each deposition layer with power of 150, 250 and 350 watts was completed with 17, 11 and 9 pulses, respectively. By increasing the power from 150 watts to 350 watts, the surface porosity decreased by about 90%.