Powder bed irregularity and hot-spot detection in electron beam melting by means of in-situ video imaging

The electron beam melting process has been successfully applied in various sectors to produce high-value-added products. Being a hot process operating in vacuum environment with x-rays and material vaporization among by-products, in-situ sensing and monitoring presents more challenges than in laser powder bed fusion. However, an automated and robust detection of unstable process conditions represents a key capability to meet challenging qualification requirements imposed by industry. This study presents novel in-situ monitoring methods based on high spatial resolution imaging for powder bed homogeneity monitoring and high temporal resolution video-imaging for hot-spot detection, i.e., the detection of anomalous local heat accumulations.