Measurement of powder bed density in powder bed fusion additive manufacturing processes
Gregor Jacob, M A. Donmez, Shawn P. Moylan, John A. Slotwinski
There are many factors influencing the additive manufacturing (AM) processes resulting in high degree of variation in process outcomes. Therefore, quantifying these factors and their correlations to the process outcomes are important challenges to overcome for widespread adoption of this emerging technology. In powder bed fusion AM process, one of these influencing factors is the actual density of the powder layers on the powder bed. This paper introduces a method to determine the powder bed density (PBD) during the actual build process. Uncertainty analysis is also presented associated with this method. The implementation example shows that the measurement method has small enough uncertainty to be able to detect small changes of PBD across the build platform due to irregularities in powder characteristics and/or the spreading mechanism.