Heat-resistant ceramic ink for coding on metal components

Fraunhofer researchers have developed an extremely heat-resistant ceramic-based ink that will enable metal components processed at temperatures over 1000°C to be marked with a code. The advantages of the technology are not simply the ability to detect production glitches and defective components at an early stage. It also opens up wide-ranging possibilities for designing process chains in the industry more efficiently and reducing their carbon footprint significantly. Even component forgeries can be prevented by means of special additives in the ink, according to the Fraunhofer Institute.

Marking components so that each one can be tracked and traced is an important requirement for the digitalisation of processes in the manufacturing industry. In metalworking industries, efforts in this area have previously failed because many metal components must be heated in individual process steps. Codes imprinted conventionally are destroyed when heated and can therefore no longer be read. Professor Thomas Härtling, group manager for Optical Test Methods and Nanosensors, and his team at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS have now developed an ink that can withstand temperatures of over 1000°C in the oven without being damaged. The Ceracode ink consists of heat-resistant ceramic particles and a glass component. In the oven, the melting glass ensures that the marking is fixed to the metal and yet is still easy to read.

The combination of Ceracode ink and the standardised data matrix code that is in widespread use in industry can provide new opportunities for the digitalisation of production processes in metalworking industries.

“The quality of every component or workpiece can be recorded along the value chain at any time, and defects can be identified right at the start of production and rectified in a targeted manner. This doesn’t just save companies energy — it also means they aren’t wasting raw materials and are able to reduce their carbon emissions,” Härtling explained.

The project is also the result of a successful collaboration. While the Fraunhofer IKTS team developed the ink and continues to work on optimising it further, project partner Senodis Technologies GmbH from Dresden is responsible for programming the software and commercialisation. Senodis Technologies is a spin-off of Fraunhofer IKTS and focuses on deploying the wide-ranging potential of the ceramic-based ink to bring about new applications for industrial customers and press ahead with the digitalisation of their value chains. It primarily targets customers from the metal, automotive and ceramics sectors.

The system of heat-resistant ink and data matrix code has reached maturity and is already available on the market through Senodis Technologies. Fraunhofer says that manufacturing companies can install the system and put it into operation with ease — even the process of retrofitting existing machinery poses no problem. The data matrix printers used as well as the scanners are compatible with existing industry standards.

In addition, the ink technology can be extensively adapted. One example is the protection of products against forgeries.

“To do this, we add special pigments to the formula of the ceramic-based inks so that they are illuminated in a defined colour under UV light. This is an interesting option for industrial customers who purchase parts consisting of particularly expensive metal alloys or components for safety-related systems,” Härtling said.

As the next step, the Fraunhofer researchers are working on how to imprint curved or shaped metal components. Further developed image recognition algorithms will then be able to read out codes precisely even on irregular or curved metal surfaces.

Image: Data matrix code on hot-formed sheet metal, printed using industrial printer. © Senodis Technologies GmbH