Evaluating Capacitive Imaging for Powder Bed Fusion Metal Additive Manufacturing

Abstract

This work evaluates the use of co-planar capacitive sensors to provide layer-wise imaging results for the Powder Bed Fusion quality control. A new sensor was designed together with a digital readout electronics which allowed for high-resolution localized measurements. The system was evaluated in different surface features produced by laser PBF with stainless steel 316 powder. Features were tested with and without the presence of the original powder with results showing that the powder presence masked the output for most of the features. This suggests that the ability of carrying charges within an alternating electrical field is similar between powder and the consolidated metal, and that, the concerning signal contribution is much higher than that caused by the conductivity difference between powder and consolidated metal.