Quality assurance in 3D printing: Inline hardness measurement developed for aerospace components

3D printing is becoming increasingly important in manufacturing, especially in the production of lightweight components for aviation. Thanks to their special structure, these components can reduce CO2 emissions and increase the efficiency of aeroplanes at the same time. However, quality assurance remains a key problem. As printed components can exhibit minor differences, they need to be fully tested before they are installed in passenger and cargo aircraft. Conventional methods such as destructive testing are unsuitable due to their high resource requirements, and complex technologies such as X-rays are also out of the question for reasons of cost and time.

In the ‘Enabl3D’ project, researchers have now developed a method with which 3D-printed components can be tested non-destructively. The testing method, which was developed by Imprintec GmbH in collaboration with the Fraunhofer Institute for Additive Production Technologies (IAPT) and VisiConsult GmbH, is based on hardness measurement, process monitoring and micro-computed tomography. These methods enable fast and reliable quality testing directly on the finished component.

One particular advance in the project is the integration of a measuring head with a 6-axis industrial robot, which allows the measurements to be carried out fully automatically. The team from the Fraunhofer Institute for Manufacturing Engineering and Automation (IPA) worked closely with Imprintec GmbH.

“Together with Imprintec GmbH, we carried out initial tests and feasibility studies in order to integrate the measuring head into series production using the robot,” explains Lukas Werdin, a scientist at Fraunhofer IPA.

Initial tests were very promising: all the desired measuring points could be reached precisely and the deviations were in the single-digit percentage range. “The deviation was in the single-digit percentage range – a very good result for an initial application in conjunction with a robot,” says Werdin.

These results provide a promising basis for the future integration of such inspection systems in series production in order to ensure the quality of 3D-printed components in aviation efficiently and reliably.