Enhanced laser beam welding

Citation

(2002), "Enhanced laser beam welding", Industrial Robot, Vol. 29 No. 2. https://doi.org/10.1108/ir.2002.04929bad.010

Enhanced laser beam welding

Applicant: University of Coventry, UKPatent number: US5866870Publication date: 2 February 1999Title: Enhanced Laser Beam Welding

This invention relates to apparatus for welding metals by use of a laser beam enhanced by a plasma arc and provides an improved welding method and apparatus. It provides a method of welding a workpiece using a plasma arc augmented laser welding apparatus having a laser and a welding head which comprises a housing, a focusing system in the housing for focusing a laser beam through a laser opening in the housing onto a workpiece and a plasma torch nozzle through which a plasma arc is established between an electrode and the workpiece.

A first power source applies a high voltage across the electrode and nozzle to strike a pilot arc which is then sustained by power from a second source. A third power source applies a high amperage signal to strike the main plasma arc between the electrode and the workpiece. The nozzle has a tip which is adapted to constrict the plasma arc and restrict its impingement on the workpiece. The nozzle and the focusing system are arranged to cause the focused laser beam and the constricted plasma arc to impinge on the workpiece at predetermined relative positions which may coincide or may be slightly spaced apart. The power sources and the laser beam are controlled by a microprocessor in accordance with a predetermined program in dependence on the type and thickness of material to be welded.