Defect Detection in LENS AM Using In Situ Thermal Camera Process Monitoring

Abstract

This study utilizes in situ thermal imaging to monitor the melt pool during a LENS additive manufacturing (AM) process. A software tool is created which gathers metrics for each frame and summarizes them over every build. Plotted metrics allow a user to visually inspect the data, but the software tool also automatically identifies anomalies and flags them for further review. Anomalies are then correlated to physical locations in the build which are inspected for defects. This type of process monitoring could lead to fast detection of defects during a build, thus increasing the confidence in production quality and eliminating the acceptance of parts with abnormalities. An anomalous event was identified by the software tool and investigated with X-ray computed tomography. Defects were observed in the location identified by the software tool.