**2. Numerical Modeling**

In order for the temperature profile to be simulated during laser welding, a finite-element model was prepared. In this case, thermophysical properties of the material, the distribution mode of the laser beam focused on the substrate, and radiated heat losses in conjunction with heat losses through the convection are considered. For this purpose, COMSOL Multiphysics software version 5.4 developed by COMSOL Inc. (Stockholm, Sweden) is utilized to carry this numerical simulation out. Simulation circumstances are similar to processing parameters performed in laser welding, including a mean power of 50–80 W, a spot diameter of 0.5 mm, a frequency of 10 Hz, a duration of 4 ms, and a welding velocity of 2 mm/s.
