Relevance of single channel signals for two-colour pyrometer process monitoring of laser powder bed fusion

Abstract

This paper discusses the relevance of two-colour pyrometers' single channel signals for process monitoring of laser powder bed fusion metal additive manufacturing. First, examples are presented where the ratio temperature provided by the pyrometer is misleading. Following is a demonstration that such instances can be uncovered by the single channel signals, where an approach for simplified signal analysis based on the working principles of the pyrometer is provided. In closing, a validation is implemented, where the careful inspection and employment of the single channel signals yielded suitable input for a successful closed-loop process control.