Conversion of in-process optical and thermal data into a single 3D file representing printing process in powder bed fusion

Abstract

Rapid development of additive manufacturing (AM) technologies leads to an increasing demand for quality control of printed parts. While in-process monitoring systems and post-testing technologies have been developed to inspect the part quality, there is not yet a well-established method that specifies the procedures and requirements to convert the extracted in-process layer-wise information into a single 3D file for quality evaluation and control. In this study, an off-axial imaging system utilizing optical and thermal cameras is deployed to acquire in-process optical and thermal images of the Powder Bed Fusion (PBF) process. Image registration and analyses are then performed on the acquired images to extract the in-process layer-wise data (e.g., coordinates, gray value, and temperature) associated with the printing process. Based on a comparison of file formats commonly used in industrial software, we select the Extensible Markup Language (XML) file format, which is specified by post-processing software, and further propose procedures for constructing a single 3D file from the in-process data to represent the printing process and evaluate the printing quality. This work provides guidelines for conversion of in-process data into 3D files and contributes to in-process monitoring and quality control of AM manufactured parts.