Numerical model of heat transfer during laser powder bed fusion of 316L stainless steel

The laser powder bed fusion (LPBF) process can be used to manufacture parts of unique design that cannot be manufactured using classical methods. The capabilities of LPBF can be expanded upon by introducing metal matrix composites to attain specific property enhancements in the created part, but technical and cost challenges exist that impede the development and advancement of this process. Further understanding of the fundamental thermal and fluid dynamic mechanisms that occur during the LPBF process is required to overcome the challenges and minimize the cost of these advancements. For this study, a numerical model of the LPBF process is created and used to explore relationships between these fundamental mechanisms. A three-dimensional, transient, finite difference numerical heat transfer model is created using MATLAB to predict the temperature and state (powder, liquid, or solid) of 316L stainless steel throughout the LPBF process. The effective thermal conductivity of the metal powder was measured using a laser pulse method for use in the model. Model results are compared to single track samples created with LPBF. The model results for melt pool area show good agreement with the physical samples.