Influence of laser power variation on Inconel 718 powder deposition profile on Inconel 738 during the AM-LMD process

In this study, in order to reconstruct defective gas turbine blades with a circular economy approach, the effect of laser power on the bonding interface in the additive manufacturing (AM) process by depositing Inconel 718 powder on an Inconel 738 substrate has been investigated. As a layer- by-layer fabrication technique, laser metal deposition (LMD) is used to product reconstruct strategic and critical parts. So, the laser powers of 150, 250 and 350 W were utilized for the deposition process on the samples. Some features such as number of pulses per layer, geometric dimensions, and microstructure of the samples were studied. It was found that by increasing the power, joint connection thickness, integrity, and substrate melting depth increased. But, higher power led to decreasing the size deviation from the design dimensions, surface porosity, and the number of pulses to complete each layer. Each deposition layer was completed via with 17, 11 and 9 pulses by using the power of 150, 250 and 350 W, respectively. Moreover, the surface porosity decreased by 90% by increasing the power from 150 W up to 350 W.