Investigation of direct laser deposition parameters of Al0.5CoCrFeNiNb0.5-Si0.1 high entropy alloy on Inconel 718

In this research, the new high entropy alloy of Al0.5CoCrFeNiNb0.5-Si0.1 was synthesized by mechanical alloying process. Then, the synthesized powder was deposited on Inconel 718 through direct laser deposition process. The effect of process parameters of laser cladding, such as laser power, powder feeding rate and scanning speed was investigated with 24 experiments for forming the optimized single-track claddings. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) equipped with Energy Dispersive Spectroscopy (EDS) were used to characterize the synthesized powders. Also, Optical Microscopy (OM) was used for investigation of geometry features and dilution of single-track clads. The XRD patterns of powder demonstrated that a singlephase solid solution (BCC) was formed after 30 hours of milling. SEM micrographs indicated the formation of solid solution after 30 hours. Also, the EDS results confirmed the compatibility of the chemical composition of the desired alloy with synthesized sample. OM images and geometrical calculations demonstrated that increasing the laser power and reducing the scanning speed led to increasing the width of single-track clad. The thickness or the height of single-track clads also was increased by reducing the scanning speed and increasing the feeding rate. Moreover, it was investigated that the laser power had the most effect on the penetration depth and dilution. The optimal conditions for direct laser deposition of synthesized powder on Inconel 718 was laser power of 500 W, feeding rate of 100 mg/s and laser scanning speed of 4 mm/s.