Melt pool modelling, simulation and experimental validation for SLM

SLM parts are built by successively melting layers of powder in a powder bed. Process parameters are often optimized experimentally by laser scanning a number of single tracks and subsequently determining which settings lead to a good compromise between quality and build speed. However, experimentation only does not yield the necessary insights into the physical processes behind the results. Therefore, the laser interaction with the powder bed must be modelled to describe the melt pool behaviour that occurs during the laser melting process. Energy absorption and heat conduction are modelled to determine the temperature distribution and characteristics of the melt pool for various process parameters such as laser power, scan speed, powder layer thickness, etc. The numerical model and simulations have been validated using measurement data obtained from SLM experiments using titanium alloy Ti6Al4V. Melt pool modelling can be used to predict SLM process parameters ranges for which single tracks are of good quality. Moreover, the simulated temperature distribution can also serve as input for methods predicting part deformation due to residual stresses.