Laser cladding gets boost from EHLA
Why is there a need for EHLA?
EHLA addresses these exact drawbacks. Thanks to the technique’s very high welding speed and low heat input, it offers deposition rates similar to thermal spraying, as well as low thermal effects on base metals, as is seen in hard chrome plating. Other advantages of EHLA are that it produces very strong bonding and dense metal coatings. Besides that, EHLA is also very resource efficient and free from toxic substances.
How does EHLA achieve these advantages?
EHLA uses a specific EHLA powder nozzle from Fraunhofer ILT, but apart from this the new process requires mostly the same parts as conventional laser cladding. Hornet Laser Cladding was therefore able to become the first system integrator for EHLA thanks to its history of building conventional laser cladding systems.
The beam quality of today’s diode lasers can achieve the requirements of some EHLA applications, so the systems are getting more interesting in terms of cost. On the system and process side there is a large amount of experience with regards to EHLA. But there is still much work to do.
On the application side there is demand for EHLA for cladding hydraulic components. It is therefore hardly surprising that the first EHLA system was set up for the offshore hydraulics industry two and a half years ago. IHC Vremac Cylinders was looking for a new coating solution with high corrosion resistance for offshore use, and thus became the first customer to use an EHLA system from Hornet. Since then we have seen rising demand for EHLA systems, in China, Australia and South Korea, driven by growing industry and environmental issues with current cladding technologies.
In cooperation with ACunity, a Fraunhofer ILT spin-off focusing on providing customised solutions for laser material processing for the Chinese market – including R&D consulting, system engineering, technical service, customer support and process development – Hornet delivered the first EHLA system in China at the Advanced Manufacture Technology Centre of the China Academy of Machinery Science and Technology (CAMTC) in Beijing. This was a starting point for a closer cooperation with ACunity that aimed to increase the penetration of EHLA technology in the Chinese market, and with this the two companies founded the EHLA consortium. The firms then began developing industrial EHLA machines integrated with advanced powder delivery technology from Fraunhofer ILT.
The first big success of the EHLA consortium was the implementation of three more EHLA systems for Chinese customers for various types of application – for example one with an inside cladding head. However, there is more opportunity than simply replacing hard chrome plating processes with EHLA, as interest grows and information is spread thanks to innovation awards like the Fraunhofer prize in 2017, the Steel Innovation Award and, most recently, the Berthold Leibinger Innovationspreis award.
One big step in the future will be the development of an EHLA system for freeform coatings, and with this, applications in 3D additive manufacturing. However, a plane surface EHLA system will be possible on a shorter timescale and will also offer a much wider range of applications.
Driving deposition - New high-speed laser cladding technologies are being developed that rival more traditional techniques