Improving metal additive manufacturing part design and final part precision using feedback from X-ray computed tomography

Additive metal manufacturing processes, such as laser powder bed fusion, still show difficulties when producing overhang features or internal structures such as channels or bores. Channels are often mutilated by sag defects and dross formation at the upper part of the channel, when the channel-axis is close to parallel to the base plate and in the particular case when support structures cannot be used as it would be impossible to remove them after the build. The problem is still not completely solved, although various design guidelines have been developed for various processes and materials in use. So far, a general approach is to tweak the processing parameters or to orient the design on the build plate to reduce downfacing regions at the most critical features of the parts. This work proposes to use feedback from X-ray computed tomography measurements and a new evaluation approach for the additive manufacturing process-chain to obtain improved geometrical accuracy of internal channels and reduced defects by adapting the parts design during the design stage