Process monitoring of meltpool and spatter for temporal-spatial modeling of laser powder bed fusion process

L-PBF is an additive manufacturing process which can produce nearly fully dense parts with complex geometry by using laser which follows layer-to-layer scanning on powder material. In-process statistical monitoring techniques are required to detect localize material spatter and control the meltpool. High speed video imaging provides process insights for identifying meltpool and spatter and can be integrated into process monitoring for L-PBF process. We demonstrate the use of high speed camera videos for in-situ monitoring of L-PBF of nickel alloy 625 to detect spatter and over melting regions to improve the process control capability. The quantities that can be measured via in-situ sensing can be referred to as process signatures and can represent the source of information to detect possible defects. The video images are processed for temporal-spatial analysis by using principal component analysis and T2 statistical descriptor for identifying the history of pixel intensity levels through the process monitoring. These results are correlated as over melting and spatter regions. (C) 2018 The Authors. Published by Elsevier Ltd.