Tools made of hard materials and ceramics such as tungsten carbide are particularly durable - but their production is challenging. Conventional mechanical processing methods quickly reach their limits when shaping these materials and lead to high tool wear. Researchers at the Fraunhofer Institute for Laser Technology ILT in Aachen have now developed a process that uses an ultrashort pulse (USP) laser to enable both the structuring and polishing of such components in a single clamping operation.
Laser processing replaces mechanical processes
The USP laser works with pulses that are just a few picoseconds short, vaporizing the material and achieving surface rates of up to 100 square centimetres per minute. The special feature lies in the flexible parameterization: while high pulse energy and low repetition rates are used to remove material during shaping, polishing is carried out at significantly higher frequencies of up to 50 MHz. The top layer of the material - between 0.2 and 2 micrometers - melts and smoothes itself due to the surface tension.
Precise polishing and targeted surface adjustment
This method can be used to smooth out micro-unevenness without changing the macroscopic structure. Selective polishing of individual areas is also possible in order to adjust certain surface properties locally or to shorten processing times. Depending on the application, laser polishing achieves surface rates of between ten and 100 square centimetres per minute.
Resource-efficient alternative to mechanical processes
The combination of structuring and polishing in a single clamping reduces set-up times and enables hard materials to be processed economically. Companies can use existing USP laser systems for additional processes or amortize investments in new systems more quickly. The process also helps to reduce tool wear and increase resource and energy efficiency.
According to ILT researchers Sönke Vogel and Astrid Saßmannshausen, the potential of the technology has not yet been exhausted. Processing rates could be further increased with faster scanners, higher laser power and larger spots. Industrial partners are invited to drive forward further development together with the ILT team.