摘要 |
<p>A plasma (13) is produced in a position where the parent metal (2) is to be welded by a laser beam (16) applied to the parent metal (2). An arc discharge (4) occurs in the direction toward the plasma (13) when the discharge electrode (12) is negative and is guided to the position where the laser beam (16) is applied. Arc electrons are produced at the point where the laser beam (16) is applied when the electrode (12) is positive, and electric discharge is caused toward the electrode (12). If the voltage applied to the electrode (12) and the parent metal (2) is an AC voltage, the polarities of the electrode (12) and the parent metal (2) alernate, causing the phenomena to alternate. If the parent metal (2) is negative, an arc discharge (4) occurs from the laser beam spot. Since the arc discharge (4) is caused from the plasma (13) produced by the laser beam (16), the arc discharge (4) is stable irrespective of the states of the parent metal (2) and electrode (12).</p> |