US 6,982,395 B2
Method and apparatus for plasma welding with low jet angle divergence
Erwin Bayer, Dachau (Germany); Philip Betz, Maulbronn (Germany); Joerg Hoeschele, Meckenbeuren-Brochenzell (Germany); Friedrich Oeffinger, Stuttgart (Germany); and Juergen Steinwandel, Uhldingen-Muehlhofen (Germany)
Assigned to MTU Aero Engines GmbH, Munich (Germany)
Appl. No. 10/471,858
PCT Filed Mar. 06, 2002, PCT No. PCT/DE02/00813
§ 371(c)(1), (2), (4) Date Feb. 13, 2004,
PCT Pub. No. WO02/076158, PCT Pub. Date Sep. 26, 2002.
Claims priority of application No. 101 12 494 (DE), filed on Mar. 15, 2001.
Prior Publication US 2004/0149700 A1, Aug. 05, 2004
Int. Cl. B23K 10/00 (2006.01)
U.S. Cl. 219—121.46 14 Claims
OG exemplary drawing
 
1. A method for plasma welding, comprising the steps of:
generating microwaves in a high frequency microwave source;
guiding the microwaves in a wave guide;
introducing a process gas at a pressure of p≧1 bar into a microwave-transparent tube which includes a gas inlet opening and a gas outlet opening, wherein the process gas is introduced through the gas inlet opening such that the process gas has a spiral flow through the microwave-transparent tube;
generating a plasma in the microwave-transparent tube by electrodeless ignition of the process gas; and
generating a plasma jet by introducing the plasma into a working space through a metallic expansion nozzle arranged at the gas outlet opening of the microwave-transparent tube.