| 摘要 |
PURPOSE:To switching welding an Al alloy with high quality and high efficiency, by using AC for TIG, overlapping optionally variable current on main MIG current and causing magnetic interference between electrodes of TIG, MIG. CONSTITUTION:TIG is performed by using AC capable of making positive current and negative current changeable optionally, and optionally variable base current Mi2 is overlapped on main MIG current. When Mi1 is peak current of MIG, ML is arc length, Ti1 is positive current of TIG, Ti2 is negative current TL is arc length, and l is the distance between electrodes of TIG, MIG, forces F1, F2 can be shown by equations I , II. At time t1, the polarity is the same and the arc attracts, and at time t2, the polarity is different and the arc repels. Accordingly, when forces F1, F2 are made nearly equal and switching is made at hundreds Hz, the arc does not change apparently, and cleaning action can be given for welding. |
