Researchers with Fraunhofer Institute for Laser Technology ILT (Aachen, Germany) and RWTH Aachen University (Aachen, Germany) have developed the extreme high-speed laser material deposition process (EHLA) that offers an economical alternative for protecting components against corrosion and wear.
The process can quickly and efficiently apply thin metallic layers, 25- to 250-µm thick, over large areas.
EHLA is a laser material deposition technique that applies high-quality, firmly bonded coatings to various materials. This process melts the powder particles while they are above the melt pool so that drops of liquid material instead of solid powder particles fall into the weld pool, which results in a nonporous, more homogenous coating layer using less base material.
According to the researchers, the process utilizes ~90% of the coating material, which conserves resources and makes the process very economical. The deposition’s thermal effect zone on the material is in the µm range, so it is possible to coat heat-sensitive components without incurring brittle phases.
The EHLA process is able to coat a component at feed rates between 50 and 500 m/min, which is 100 to 250 times faster than speeds with conventional laser material deposition. Various materials can be used for EHLA coatings, such as iron, nickel, and cobalt-based alloys.
In addition, completely new material combinations are possible, such as coatings on aluminum-base alloys or grey cast iron.