Thermal modeling of Inconel 718 processed with powder bed fusion and experimental validation using in situ measurements

A model for predicting the thermal response of Inconel® 718 during laser powder-bed fusion processing (LPBF) is developed. The approach includes the pre-placed powder layer in the analysis by initially assigning powder properties to the top layer of elements before restoring the solid properties as the heat source traverses the layer. Different linear heat inputs are examined by varying both laser power and scan speed. The effectiveness of the model is demonstrated by comparing the predicted temperatures to in situ experimental thermocouple data gathered during LPBF processing. The simulated temperatures accurately capture the measured peak temperatures (within 11% error) and temperature trends. The effect of neglecting the pre-placed powder layer in the simulations is also investigated demonstrating that conduction into the powder material should be accounted for in LPBF analyses. The simulation neglecting the powder predicts temperatures more than 30% higher than the simulation including the powder.