Study On Character Of Low-power Laser+Arc Hybrid Welding

In this paper, the character of low power YAG laser+arc hybrid welding on AZ31B magnesium alloy and Q235B mild steel is investigated. The main conclusions can be drawn as follws.1. With the appropriate parameters, the eminent welding joint of AZ31B magnesium alloy welded by low-power laser+TIG arc hybrid can be obtained. The penetration of hybrid welding is about 4.82mm, which is about four times as deep as those of TIG welding. Compared with the arc shape of TIG, the root of arc is compressed.2. The YAG pulse laser energy is distributed by adjusting current, pulse duration and frequency, and the influence of laser waveform in laser welding and YAG laser+TIG hybrid welding on welding penetration is studied. Results show that when the pulse duration of high power density pulse is no more than 0.2ms in laser welding and 0.4ms in hybrid welding, respectively, the welding penetration of laser with high power density pulse is deeper than that of lase without high power density pulse.3. In the MAG welding and laser+MAG hybrid welding on Q235B mild steel, the influences of arc current and laser power on welding velocity and inclination angle of welding plate are investigated. And results show that in the downhill welding, with the increasing of arc current and laser power, the critical welding velocity and inclination angle increase. Moreover, the variation tendency of welding velocity and inclination angle is consistent.4. To obtain the welding joint with deeper penetration, the adjustable range of pulse duration of high power density pulse of YAG laser is 0.1-0.2ms in laser welding and 0.1-0.4ms in hybrid welding because of the addition of YAG laser and the attration and compression effect between laser and arc. The pulse duration of laser, which can increase the welding penetration, is 3.0-3.2ms in laser welding and 3.0-3.4ms in hybrid welding. Compared with the MAG welding, with the same welding current, voltage and wire extension, the critical welding and the critical inclination angle of hybrid welding is greater.