LBMCheck - Optical Quality Assurance in Laser Beam Melting (LBM) using Camera and Photodiode
sponsored by FFG, opens an external URL in a new window
Project number: 859775
Project end: April 2020
The basis of the R&D project LBMcheck is the additive manufacturing process called LSS (Laser Strahl Schmelzen)/LBM (Laser Beam Melting), the 3D printing of metallic materials, whose potential cannot yet be fully exploited due to a lack of quality assurance and documentation options. The strengths of the process are undisputed and lie in the very flexible production possibilities from individual components (batch size 1) to series production, which is why the process is of great interest especially for space travel (can be seen in the ESA Additive Manufacturing Roadmap v1.3, as well as the nationally coordinated AM initiative of the FFG ALR). Furthermore, there is an efficient use of resources and raw materials due to additive manufacturing (only what is necessary for the component function is built) and an almost complete recyclability of the non-melted powder material. In addition, the unique design freedom of the process should be mentioned, which enables the generation of the most complex and highest quality components, which is of particular interest to the aerospace industry. Systems available today for LSS do not yet allow complete quality assurance of the component quality, but only the detection of process anomalies. It would be absolutely necessary to reliably detect actual defects in three dimensions in order to enable a complete process documentation of the construction job as well as a complete documentation of the component quality (transparency and traceability).
The aim of the project is to realize a quality assurance of the component quality with the help of a combined photodiode- and camera-based melt pool monitoring during the laser beam melting of metals. Systems available today only detect process anomalies, but not actual component defects in the sense of a defect catalog. With the help of the proposed combined photodiode and camera-based melt pool monitoring, it should be possible to detect and subsequently categorize actual defects in three dimensions.
The most important result of the project is the availability of a quality assurance of the component quality at the LSS on the basis of a novel combined photodiode- and camera-based melt pool monitoring. Another result are algorithms for the calculation of the characteristics, which allow the modeling of the component quality from the sensor data (photodiodes and camera). These algorithms shall preferably operate under avoidance of reference data. Furthermore, a classification strategy shall be developed, which allows the mapping of individual quality requirements. With all these results, a complete process documentation of the construction job as well as a complete documentation of the component quality (transparency and traceability), as it is required in safety-critical industries (in case of danger for humans and/or machines by 3D-printed components), can be enabled, whereby the technology readiness level of the LSS process can be increased immensely.