Numerical investigation of thermal behavior during the laser-assisted directed energy deposition process for additive manufacturing

In this study, we use the laser-assisted directed energy deposition (DED) method on an Inconel 901 plate to carefully examine the thermal behavior of the material. The thermal characteristics of the substrate are explained using both experimental and simulation methods. The laser's power, which ranges from 550 to 750 W, and its scanning speed, which varies between 6.67 and 10.0 mm/s, are among the variables covered by this study. For various laser powers and scanning speeds, we have thoroughly examined the duration of cooling which occurs between the melting and cooling periods in the area situated beneath the top surface of the substrate. Under various circumstances related to laser-assisted DED techniques, variations in temperature under the top surface of the substrate have also been calculated. Our results show that increased heat conduction from the heat source to the substrate causes the molten pool's lifetime to increase with increased laser power and decreased scanning speed. The conditions that operate at 550 W, 8.33 mm/s and 650 W, 10 mm/s have shorter molten pool lifetimes and faster cooling rates, resulting in smoother surfaces than the other conditions. The conclusions drawn from this work highlight how our study offers a deeper understanding of the internal melting and cooling processes that take place within the molten pool during laser-assisted DED methods.