According to Greenstone-Tech, Fraunhofer Institute for Laser Technology (Fraunhofer ILT) has developed the EHLA (Extreme High-Speed Laser Material Deposition) technology, which is considered an efficient and environmentally friendly solution. EHLA offers significant sustainability advantages, particularly for coating metal components exposed to extreme stresses, which need to be protected from corrosion and wear. Today, the EHLA technology has been upgraded, and Fraunhofer ILT scientists, in collaboration with their partner Ponticon, have developed the patented process now known as EHLA 3D, aimed at advancing its applications in manufacturing.

Laser Cladding for Critical Metal Components in Extreme Conditions

Metal components are often exposed to extreme conditions, such as those used in aerospace, offshore oil drilling platforms, coal machinery, paper rolls, hydraulic cylinders, or automotive brake discs. These parts require specialized coatings to protect the material from corrosion and rapid wear. With technological advancements, the market demand for repairing these components has grown. This demand focuses on reducing production time for personalized, high-performance component repairs or manufacturing while also meeting significant price pressures.

However, no conventional process previously met these standards. Existing processes were either inflexible, inefficient, or economically insufficient to apply high-quality metallurgically bonded thin metal layers onto component surfaces. The hard chrome plating process was approved in the EU only since September 2017 due to the environmental damage caused by the electrochemical deposition of toxic chromium (VI).

EHLA Technology: A Revolutionary Alternative

To address this gap, Fraunhofer ILT scientists developed an alternative coating process: EHLA (Extreme High-Speed Laser Material Deposition). EHLA has been applied in industrial sectors since 2015, particularly for coating manufacturing.

Perfect Foundation for Future Development

Compared to traditional methods, EHLA scores in several key areas, including feed rate and deposition thickness. In 2017, Fraunhofer ILT scientists were awarded the prestigious Joseph von Fraunhofer Prize for their development of EHLA. This technology has significantly enhanced the feed rate for surface treatment in traditional laser material deposition from 0.5 meters per minute to 2 meters per minute and even up to 50 to 500 meters per minute. As a result, the coating speed has increased by 100 to 250 times, with significantly thinner layers being applied.

One of the main advantages is the low heat input. In traditional laser material deposition, powder filler material is melted directly on the component surface in a relatively large molten pool, permanently altering the material properties and consuming a lot of energy. In contrast, EHLA works by melting solid powder particles while still in the air. They reach the surface in a liquid state without further melting under high energy input. This results in a heat-affected zone (HAZ) of only five to ten microns, compared to a much wider HAZ in conventional processes.

This breakthrough enables the pairing and processing of metallurgically incompatible, heat-sensitive materials, such as aluminum and titanium. Overall, the surface of the components is much smoother, with a roughness just one-tenth of that produced by traditional deposition methods. This provides the perfect foundation for further development steps.

Next-Generation Additive Manufacturing with EHLA 3D

In principle, EHLA is suitable for all rotationally symmetrical objects that can be processed on high-speed rotational motion systems, but when extremely high speeds combined with high precision are achieved, the technology can be applied in even broader fields.

Since 2017, Fraunhofer ILT’s team has been developing a new generation of processes: EHLA 3D, which integrates the innovative EHLA technology into faster 3D printing operations. The primary focus of the research is to identify the special requirements for system technology that must meet the demands of extremely high speeds and precision in order to combine EHLA with high-speed 3D printing.

EHLA 3D not only achieves freeform surface processing but also offers several unique advantages related to the process: high build rate, tremendous flexibility, material diversity, and high precision. In the near future, this technology will enable industries to easily and cost-effectively mass-produce complex structures, with personalized components being a possible outcome.

First Prototype and Future Development

The first prototype of this system was successfully launched in 2019 in collaboration with Ponticon in Wiesbaden, Germany. This prototype was based on a tripod motion principle, using a structure with three linear motors connected to the build platform through rods. The workpiece moves on the platform. It operates similarly to a magnetic levitation train, where the special structure compensates for inertial forces, allowing the platform to move very quickly and precisely without causing significant vibrations. The system can currently process components weighing up to 25 kilograms, with a gravitational acceleration of up to five times and a speed of up to 200 meters per minute, while maintaining a high precision of 100 microns.

To make the EHLA 3D process accessible to a wide range of industrial users, Fraunhofer ILT is currently conducting targeted research to manage the complexities of the system. Core areas of this research include process monitoring concepts and automated path planning tools. During process development, precise coordination of all parameters is required: speed, laser power, and powder volume, depending on the material combination being processed.

EHLA 3D’s Impact on the Manufacturing Industry

EHLA 3D significantly expands the range of possibilities for component production and processing, making the process much more efficient and environmentally friendly. Currently, in an industrial project at the International Center for Turbomachinery Manufacturing (ICTM), several renowned companies from the aerospace and turbomachinery industries are experimenting with the EHLA 3D processing technology. Fraunhofer ILT’s follow-up research projects were submitted for funding in 2022, with additional bilateral and government-funded joint projects planned.

Abschluss

In conclusion, EHLA 3D has revolutionized the additive manufacturing and repair sectors, offering a breakthrough solution for creating high-performance metal coatings with speed, precision, and environmental sustainability. Its integration with Laserauftragschweißen technologies has the potential to significantly transform industries requiring durable and precise component repairs, including aerospace and turbine manufacturing. As the EHLA 3D system becomes more accessible and refined, it is expected to become a key tool in the future of manufacturing, offering companies cost-effective and high-quality solutions.