Thanks to the use of EHLA and EHLA3D by Makino and the Fraunhofer Institute for Laser Technology ILT, the limits of additive manufacturing have been redefined. By integrating EHLA3D into a five-axis CNC platform, it is now possible to efficiently produce, coat or repair complex geometries with high-strength materials.
The research collaboration shortens production times and extends the service life of components in critical industries, while at the same time laying the foundations for future innovations in the circular economy.
Laser technology in manufacturing technology
Laser technology plays a central role in manufacturing technology, especially in the field of additive manufacturing. Makino, a machine tool manufacturer headquartered in Japan, and the Fraunhofer Institute for Laser Technology ILT dared to make a technological advance: they wanted to transfer the extreme high-speed laser cladding EHLA to a five-axis CNC platform.
However, this required the development of kinematics that would enable the machining head to move quickly and dynamically for the EHLA process. This would allow a wide range of geometries to be implemented flexibly, and components could be coated with an enormous range of materials. After the project partners initially only thought about additive manufacturing, the topic of repairs soon came up:
"Repairs are extremely exciting," explains Min-Uh Ko, group leader for additive manufacturing and repair LMD at Fraunhofer ILT. "Many expensive components have to be replaced even if there are minor defects. A flexible system like Makino's with a rotary and tilting table actually offers good repair options, which saves costs for new production, avoids transport and delivery times, and minimizes downtime. And: The topic of repair is the basic prerequisite for a future circular economy."
Newly designed process control
Makinos was not only responsible for the CNC hardware in the project, but also for the process control, which had to be completely redesigned. The challenge was to technically adapt the machine to high accelerations and to optimize the process control and machine kinematics to precisely control the interaction between the laser beam and the material.
The machine tool, which was developed by the Makino branch in Singapore, achieves an effective feed rate of up to 30 meters per minute, which represents a significant increase over conventional systems. This speed is particularly advantageous when machining large and complex components, as it significantly shortens production time. The technical improvements lead to a consistently high quality of the end products and improved economic efficiency of the manufacturing process, which is particularly important for high-quality components in the aerospace and toolmaking industries.
"Makino is known worldwide for its high-precision CNC systems. The step into additive manufacturing, especially the high-speed LMD, represents a strategic expansion of the Makino portfolio. The jointly developed five-axis CNC machine now makes it possible to produce complex geometries in difficult-to-weld materials such as high-strength steels or hard metal quickly and precisely. This is unique,” says Makino’s project manager Dr. Johannes Finger.
Efficiency and precision
The ILT contributed its extensive expertise in the field of laser-based manufacturing processes and brought its extensive infrastructure and specialized laboratory facilities to the project. With experience in process and component development for LMD, the institute played a decisive role in optimizing the process parameters for processing various materials and ultimately transferring the new technology to the industrial pilot customer toolcraft AG. This included adjusting the laser parameters, fine-tuning the powder feed and optimizing the motion control of the CNC machine.
“Optimizing the heat input is a critical aspect of the EHLA3D process,” says proven materials expert Min-Uh Ko. “The feed rate and the powder gas jet play a crucial role in controlling the heat that is introduced into the material. By adjusting the feed rate and the powder mass flows, the heat input can be precisely controlled, which leads to a reduction in the heat affected zone and ensures a uniform coating quality.”
"By using high feed rates and optimized powder feed, a significantly improved efficiency of material application is achieved with the same or even higher precision. The build-up rate for HS-LMD can thus be significantly increased, which leads to an increase in the overall efficiency of the manufacturing process," explains Johannes Finger.
High-performance components
One of the project goals was the repair and maintenance of high-quality tool and machine parts that are exposed to high loads in regular operation. The partners were able to implement this with the adapted EHLA3D technology. In addition, EHLA3D technology was successfully used to coat wear parts, which significantly improves the service life of these components. By being able to apply wear-resistant layers precisely and efficiently, EHLA3D offers a cost-effective solution for extending the service life of components in various industries, including mining and heavy industry.
Fast results
The fact that Makino was able to implement the results so quickly in the new AML 500 processing machine shows, on the one hand, how flexible the machine manufacturer's CNC systems are. The practical applications also show that EHLA3D technology is not just a theoretical concept, but an advanced, robust and industrially applicable technology that offers significant advantages in terms of cost, efficiency and performance. The collaboration between the industrial customer and Fraunhofer ILT has thus led to tangible improvements in manufacturing technology that go far beyond the laboratory environment.
A key aspect of future developments will be the identification and validation of new areas of application for the EHLA3D process. Thanks to the new flexibility of the processable material systems, the extended EHLA process can now be transferred to areas of application that could not usually be investigated due to the limitations of the LMD process. This particularly applies to applications with multi-material systems and the printing of fine structures.
