In Operando Monitoring by Analysis of Backscattered Electrons during Electron Beam Melting

Abstract

Additive manufacturing by electron beam melting (EBM) is a complex process, which still lacks reliable tools for process monitoring. Demanding processing conditions such as high temperature, high vacuum, and X-ray radiation impede the continuous operation of standard process monitoring devices such as light-optical camera systems. To overcome this deficit, the detection of backscattered electrons (BSEs) is a highly promising approach. A detection system for BSEs is used for recording the in operando signal during melting inside an EBM system. The acquired data are postprocessed by mapping the data points to spatial coordinates. A comparison between the obtained intensity map and the as-built surface shows a remarkable correlation, which might be suitable for process monitoring and quality control purposes.