Process digitization in the metal industry

The individual recording of manufactured components is a prerequisite for the digitalization of production processes, as this is the only way to combine production parameters and component status. Special challenges arise in metal processing and the production of ceramics. While cold-produced metal components have been marked for a long time, high process temperatures of up to 1300 °C prevent consistent marking of other components. The melting of surfaces, tarnishing, scaling and potentially occurring corrosion make conventional markings impossible in many cases.

The Ceracode^® technology

Fraunhofer IKTS has developed the high-temperature-resistant Ceracode^® ink for these difficult applications. This ink is used to print markings (such as data matrix codes) on metal or ceramic components using standard industrial printers before they are further processed in high-temperature steps. The high temperature causes the ink components to bond with the component surface, resulting in a permanent marking. Component marking is already used during press hardening in production lines at car manufacturers. This forming technology is used to produce high-strength crash-relevant body elements such as A, B and C pillars or battery boxes. The marking process has passed the technology development stage and is available as a product.

In addition to the customization of ink and printing parameters, Fraunhofer IKTS is also tackling new applications that go beyond pure component identification (track-and-trace).

Opening up new applications in process digitization

In addition to recording the code content (e.g. consecutive production number), the marking allows process parameters (such as oven dwell times, pressing forces, tools used) to be assigned to individual components. This increases the granularity of digital process monitoring and can be used for optimization via a digital twin of the manufacturing process. On the other hand, the marking process itself can also be monitored and thus made highly reliable by automatically analyzing the print image immediately after printing.

Fraunhofer IKTS pursued the latter in the BMWK joint project “Ceracode Digital” (funding code: 16GP105802). Automated image segmentation (differentiation between print pattern and background) allows the smallest deviations, e.g. of print dots from their target position, to be detected. The characteristics of the print determined in this way allow early detection and prevention of print failures. In addition, it is also possible to verify the authenticity of components, which will be of great relevance in the future, e.g. for recording component-specific CO₂ footprints.