Multi-Scale Modeling of Laser Cladding Process (Preprint)

摘要

Laser cladding is an additive manufacturing process that a laser generates a melt-pool on the substrate material while a second material, as a powder or a wire form, is injected into that melt-pool. Among all laser manufacture processes, laser cladding offers the most extensive variety of possibilities to alter a component at its surface. Despite immense potentials and advancements, the process model of microstructure evolution and its coupling with macro parameter of laser cladding process has not been fully developed. To address this issue, a process model of microstructure evolution has been studied by utilizing a phase-field method. Phase-field method has become a widely used computation tool for the modeling of microstructure evolution with the advantage of avoiding of tracking the interface explicitly and satisfying interfacial boundary conditions. In present work, the numerical solutions of a phase-field model are analyzed. The connection of macro-process and microstructure evolution is examined by considering the relationship of macro- and micro- parameters. The effects of thermal noise and melt undercooling on the final microstructure have also been studied. The prediction results are compared with other researchers' results and good agreement was found. Different solidification morphologies of different locations in the melt pool are also investigated. It was found that not the mass transfer but the heat transfer in the melt pool dominates the solidification process.