Laser metal deposition is becoming autonomous and sensor-driven
Mining tools experience mechanical and abrasive stress throughout their lifespan. Harsh operating conditions accelerate tool deterioration while time and safety considerations add repair pressure from all sides.
Laser metal deposition
Laser metal deposition (LMD) is a process where metallic filler material is applied locally to a substrate using laser radiation. The laser, acting as a precise and energy-efficient heat source, selectively melts the material as the processing head moves relative to the component. LMD can be used for functional coatings, component repair, or additive manufacturing of new parts.
“One of the key benefits of LMD is its targeted and rapid energy input, which enables precise thermal control. This minimises residual stresses, distortion, and undesired structural changes, making the process suitable even for delicate or thin-walled components,” says member scientist at the Fraunhofer Institute for Laser Technology (ILT) Max Zimmermann.
The Aachen-based research institute develops laser beam sources, optical components and systems, photonic technologies and laser material manufacturing processes. This includes the field of LMD.
The AI-SLAM project
In LMD, preparing and programming the machining paths is time-consuming and labour-intensive. The AI-SLAM project addresses this challenge, aiming to make the entire LMD process autonomous and sensor driven. A Canadian-German consortium has been formed for this purpose, consisting of Braintoy, Apollo Machine & Welding Ltd, BCT Steuerungs- und DV-Systeme GmbH, McGill University and Fraunhofer ILT, funded by the Federal Ministry of Education and Research BMBF and the National Research Council of Canada NRC.
The resulting system integrates laser scanning, automated path planning and AI-supported parameter optimisation and quality assurance. AI predicts optimal process parameters, detects defects and ensures high reliability even when dealing with varying geometries, materials, or component conditions.
“AI serves as an intelligent support tool, taking over routine tasks.” says Zimmermann, the AI-SLAM project manager,
The AI analyses sensor data – such as geometric scans, thermographic images, and process signals – to determine key LMD parameters such as laser power, feed rate, and powder mass flow. The system can detect issues such as pores, bonding defects, or insufficient layer overlaps, in some cases even in real time during the process.
“This semi-automated process significantly reduces the time needed for setup and improves process stability, even for unknown or non-uniform components,” says Zimmermann.
Extreme high-speed
The Institute is also developing extreme high-speed laser material deposition (EHLA). Powder is melted by the laser beam while still in flight above the component, allowing for extremely high feed rates – several hundred metres per minute compared to just a few metres per minute in conventional LMD. This enables the deposition of thin, dense, and well-adhered layers, typically 25µm to 300µm thick, while increasing productivity.
The LMD and EHLA are compatible with almost all metallic materials, as well as stainless steels, bronzes, and high temperature alloys. Applications include:
-
Drill heads and chisels – protection against abrasion from hard rock
-
Bucket teeth and loading shovels – extended service life through hard coatings
-
Conveyor screws and pump components – resistance to erosion and cavitation
-
Crushing tools – targeted wear protection in high-stress zones
For more information, visit: www.ilt.fraunhofer.de
