Among the various phenomena involved in laser cladding, the solidification of molten pool has been of a great interest for years. Despite the remarkable advances and big potentials in this area, the modeling of microstructure evolution and its coupling to macroscopic parameters have not been properly studied. In the present work, the solidification of molten pool in laser cladding process is studied using a multiscale modeling based on the phase field method. The finite element method and the COMSOL code are used to solve the system of equations. First, the laser scanning on the substrate is simulated and the mass addition is considered such that the predefined microelements of the additive mass are activated along with the laser motion based on a specific pattern. Simultaneously, the shape and geometry of the molten pool and the temperature field are calculated. Next, different types of solidification behaviors such as equiaxed and columnar for pure nickel are studied in the microelements inside the solid-melt interface using the phase field method. Numerical procedure is verified based on different microstructures and solid-melt interface velocity compared with those of previous studies. Also, the effect of key parameters on solidification such as undercooling, solid-melt interface width and velocity, laser power, thermal gradient and solidification average velocity for different depths is investigated. Keywords: Laser cladding process, phase field method, solidification, molten pool, finite element simulation
