Detecting spattering phenomena by using high speed imaging in L-PBD of 316 L

Abstract

High-speed imaging is nowadays a widely used monitoring system in laser based powder bed fusion (L-PBF), because it enables observation of the occurring process phenomena. The quality-price ratio of the high-speed cameras has significantly increased over the last few years, and therefore it is a more suitable method for monitoring. This study concentrates on preliminary understanding of the spattering phenomena based on theoretical background and experimental findings. A better understanding of the spattering phenomena provides a possibility to achieve better part quality more cost-efficiently and to optimize the quality control during the process. According to the results of this high-speed imaging study, spattering is in the key role of the build part quality in L-PBF. The spattering phenomena can be categorized into three different types: entrainment driven spattering, recoil pressure driven spattering and Marangoni effect. These types are linked to the melt pool modes and can be detected from different amounts and sizes of the spatters.