| Abstract Scope |
High-temperature build plate preheating is an effective method to reduce part distortion in the laser powder-bed fusion (LPBF) process. It also leads to changes in the powder quality, including sintering which is expected to alter the thermal conductivity in the powder bed. This presents a challenge for part-scale distortion modeling where convection is often used to represent heat loss into the powder bed to reduce computational load. In this work, experimental measurements of the temperature profile in a powder bed are taken at build plate temperatures up to 500°C. Oxidation and sintering of Inconel 718 powder are measured over a period equivalent to a LPBF build. Through calibration of thermo-mechanical models to experimental temperature measurements, time and temperature dependent convection coefficients are used to improve distortion predictions. This provides a comprehensive view of the effect of build plate preheating on thermal history, part distortion, and powder quality in LPBF builds. |