Researchers at Germany’s Fraunhofer Institute for Laser Technology ILT in Aachen, as well as the RWTH Aachen University, are reported to have developed an ultra-high-speed laser material deposition process, known by its German acronym EHLA, to protect components against corrosion and wear. On May 30, 2017, the research team was awarded the Joseph von Fraunhofer Prize in recognition of this work.
A number of techniques already exist to protect components against corrosion and wear, such as hard chrome plating, thermal spraying, laser material deposition or other deposition welding techniques. However there are downsides to these processes, state the researchers, such as the need to require authorisation for chromium (VI) coatings as of September 2017. With ultra-high-speed laser material deposition, or EHLA, the researchers have developed and patented an alternative process to overcome the shortcomings of the conventional processes in the areas of coating technology and repair.
“We can now use EHLA to apply thin layers in the range of a tenth of a millimetre over large surfaces within a short time, while being resource-efficient and economical,” stated Dr Andres Gasser, Group Manager at Fraunhofer ILT.
It was stated that components can be coated 100 – 250 times faster using EHLA than with conventional laser material deposition, with minimal heating of the substrate. Thus, EHLA facilitates the coating of heat-sensitive components, which was impossible due to excessively high heat input up to now. Also, the new process can be used for completely new material combinations such as coatings on aluminium base alloy or cast iron.
In close cooperation with ACunity GmbH from Aachen, Germany, a spin-off of the Fraunhofer ILT, the Dutch company Hornet Laser Cladding B.V. will deliver the first EHLA system to China in the near future. It will be used for research purposes and industrial applications at the Advanced Manufacture Technology Center of China Academy of Machinery Science & Technology CAMTC in Beijing.