Utilizing Total Electron Emissions for Part Qualification and Failure Prediction

Electron beam powder bed fusion (EB-PBF) is an additive manufacturing process that has seen application in the aerospace and medical industries due to its ability to generate complex geometries with difficult to process materials. However, defects present in parts manufactured via EB-PBF have limited its greater adoption in industry, prompting research into in-situ process monitoring for the EB-PBF process. A recently popular method for in-situ EB-PBF monitoring has been the collection and evaluation of the total electron emissions (TEE) produced when the electron beam interacts with the powder bed. Defect, composition, and topographical information has been demonstrated to be able to be collected via TEE monitoring.

While defects have been shown to be able to be sensed by TEE monitoring, there is a lack of application of this information to predict part performance in the literature. As such, this study presents a method for utilizing in-situ TEE data to predict mechanical part life. Rotating beam fatigue bars are printed using the EB-PBF process and are scanned in-situ for TEE information. The collected information is used to identify critical defects present in the part, and a mechanical model is applied to predict part lifetimes based off of the TEE defect information. The collected defect information is validated via comparison to computed tomography scans, and the mechanical model the validated by the results of the rotating beam fatigue testing.