Laser-beamwelding

An arrangement of work stations for use in the assembly by welding of metal plates comprising:

• a high-intensity laser beam generator generating an unfocussed laser beam, said laser beam having power in the range of 5 to 25 kW;
• reflective means defining an optical path of said unfocussed beam;
• at least two workstations at separate locations within a workflow sequence, each said workstation comprising a laser beam focussing head;
• and reflective means at each said workstation selectively positionable into said optical path to reflect an unfocussed beam to said focussing head;
• in which at least one workstation comprises in association with the said focussing head (a) means for feeding to said focus a beam-interceptor wire and (b) gas-supply means directed towards said focus to localise and contain the energy-transferring plasma generated by the inpingement of the focussed beam on the interceptor wire.

A method for the welding together of portions of metal plate comprising the steps of:

• locating the portions to be welded in as close contact as their surfaces permit;
• causing a focussed high-energy laser beam to travel along the said line of best contact;
• continuously feeding a separate beam-interceptor wire so as to locate it generally at the beam focus, said interceptor wire being of a material compatible with the material of the plate;
• and directing a supply of gas towards the beam focus to at least partially confine a plasma at least partially formed by impingement of the focussed beam upon the interceptor wire.