Laser processing of materials

Laser beams are used in cutting, welding, and also in surface processing techniques such as hardening, remelting, and removal. The temperatures required for igniting, melting, and vaporizing the material can be achieved by focusing the laser beam in a very small focal spot using a lens or mirrors of the processing head.

The focal spot is positioned at varying heights relative to the workpiece e.g. at the upper surface of the workpiece when laser cutting with oxygen, in the workpiece during laser welding or close to the underside of the workpiece in laser cutting with nitrogen.

One can, though, deviate significantly from these general rules when certain materials, the desired production quality, the production process or the available beam intensity mandate a different focal position. Focusing can be entirely unnecessary in hardening and other surface treatment processes where the laser beam is unfocused and processes a large surface per operation.