关键词: selective laser melting, powder bed fusion, finite element modeling, laser absorption

Abstract: Laser powder bed fusion (LPBF), like many other additive manufacturing techniques, offers flexibility in design expected to become a disruption to the manufacturing industry. The current cost of LPBF process does not favor a try-and-error way of research, which makes modelling and simulation a field of superior importance in that area of engineering. In this work, various methods used to overcome challenges in modeling at different levels of approximation of LPBF process are reviewed. Recent efforts made towards a reliable and computationally effective model to simulate LPBF process using finite element (FE) codes are presented. A combination of ray-tracing technique, the solution of the radiation transfer equation and absorption measurements has been used to establish an analytical equation, which gives a more accurate approximation of laser energy deposition in powder-substrate configuration. When this new analytical energy deposition model is used in in FE simulation, with other physics carefully set, it enables us to get reliable cooling curves and melt track morphology that agree well with experimental observations. The use of more computationally effective approximation, without explicit topological changes, allows to simulate wider geometries and longer scanning time leading to many applications in real engineering world. Different applications are herein presented including: prediction of printing quality through the simulated overlapping of consecutive melt tracks, simulation of LPBF of a mixture of materials and estimation of martensite inclusion in printed steel.

Key words: selective laser melting, powder bed fusion, finite element modeling, laser absorption