Numerical simulation of interaction between metal powder and melting pool during laser rapid forming

During LRF, the melting pool free surface serves as a moving window of laser power and powder mass input and a dynamic boundary of the LRF continuous growth domain, so the interaction between laser, powder and melting pool free surface is the basic problem that should be coped with in LRF process. The melting pool transient temperature field and gas/powder two phase fluid field numerical model are established. Using finite element birth and death technology, the growth of cladding layers and shape of melting pool free surface are simulated, and using Lagrangian particle tracking model and momentum loss (parallel and perpendicular) option, the interaction between melting pool free surface and powder such as capture and reflect was simulated. At last, the interaction between 316 L stainless steel powder, laser and melting pool free surface was calculated, and the numerical result is in agreement with that of the experiment.