Laser ablation is the process of removing material from a solid surface by irradiating it with a laser beam. The material is heated by the absorbed laser energy of the laser spot and evaporates or sublimates.
Laser energy can be selectively absorbed by coatings, particularly on metal. Pulsed lasers can be used to clean surfaces, remove paint or coating, or prepare surfaces for painting or welding without damaging the underlying surface. High power lasers clean a large spot with a single pulse. Lower power lasers use many small pulses which may be scanned across an area. The advantages are:
– It is relatively easy to automate.- The running costs are lower than dry media or Dry-ice blasting, although the capital investment costs are much higher.- The process is gentler than abrasive techniques, e.g. carbon fibres within a composite material are not damaged.- Heating of the target is minimal.
|– No solvents are used, so it is environmentally friendly and operators are not exposed to chemicals.|
Laser ablation is often the step before Tailored Welded Blanks are laser welded together. Before the blanks are welded together, the thin anti-corrosion coating in the welding area must be removed. This is often done by laser ablation. Two 1.5 mm laser beams, one for each side of the blank, move over the edge of the blanks and remove the anti-corrosion layer.
The LAU 3150 tw is designed for the simultaneous linear ablation of the top and bottom edge of coated metal tailored blanks. By vaporizing the coating, the blanks can be welded together in a later stage of the production process on another machine. The picture above shows the machine.
The machine has two tables: while the blanks on one table are ablated in the machine, the other table is moved outside the machine to be unloaded and reloaded.
Each laser is is connected to an ablation head via a fiber: one downward ablation head to ablate the top of the blank and an upward ablation head to ablate the bottom of the blank.
The machine can be loaded and unloaded by hand or by robot.