Laser in Vacuum supports supreme metallurgical properties of molten material.
Laser Beam Generation - Principle
A laser emits a beam of electromagnetic radiation that is monochromatic, collimated and coherent. Lasers consist of three main components: - a pumping source: supply of stimulating energy - laser medium: solid, liquid or gas
- an optical resonator: fully reflective mirrors and partially reflective mirror, which enables emission of beam.
Spatial coherence allows tight focusing of a laser and the beam stays parallel over great distances:
this is called "collimation".
Temporal coherence emits light pulses in ultrashort femtoseconds with a very narrow wavelength spectrum, i.e. a single color of light.
Principle of Laser Beam Generator - Source: Springer
Laser in vacuum machining requires requires ≤ 100 mbar in the working chamber. The picture sequence below shows the impact of vacuum pressure on spatter behaviour.
Often only a single forepump can evacuate the chamber. The vacuum chamber and its designed cnfines the laser beam and potential reflections reliably in order to meet the safety requirements.
Evobeam's laser in vacuum machining systems use pumps that minimize the evacuation time to increase productivity and production rates.
Impact of vacuum conditions on spatter with laser beam machining
p = 1013 mbar
p = 500 mbar
p = 100 mbar
p = 10 mbar
Fields of application
Most common laser in vacuum applications are welding and cladding.
Laser in Vacuum Welding
As compared to atmoshperic pressure, Laser in Vacuum Welding can create much deeper and narrower seam with minimized heat input into the metal.
Warpage of the workpiece is significantly reduced or even avoided.