Parametric Study of Microstructural Properties at Laser Cladding

Self-consistent numerical model of laser cladding with coaxial powder injection has been developed. The model takes into account the heat transfer, hydrodynamics, solute transport, and phase transition kinetics. The additive process is numerically analyzed using the open-source computational fluid dynamics (CFD) package. The S-CLSVOF program is adapted for modeling heat and mass transfer and free boundary evolution of the melt pool. The phase transition is modeled using the Johnson-Mehl-Avrami-Kolmogorov equation with allowance for nonuniform temperature distribution on the melt pool surface. The clad-layer microstructure is investigated as a function of the process parameters. High scan rate is shown to result in a finer grain size of clad layer structure. The data obtained can be used for construct a cladding process map.