2219-T87高强铝合金复合超高频脉冲方波VP-GTAW焊缝成形特征

采用平板堆焊工艺进行2219-T87高强铝合金焊接,研究了复合超高频脉冲方波变极性钨极氩弧焊接(HPVP-GTAW)过程中超高频脉冲方波电流特征参数对焊缝熔透成形的影响.结果表明,在正极性有效电流保持基本一致(变化范围±5 A)条件下,与常规VP-GTAW电弧焊接相比,超高频脉冲方波电流的加入可提高2219-T87铝合金焊缝的熔透率,焊缝熔透率增加20%以上;脉冲电流频率对焊缝熔透率有明显影响;在一定范围内增加脉冲电流幅值,减小占空比,可显著提高焊缝熔透率,脉冲电流幅值100 A和占空比20%时,焊缝熔透率增加75%以上.

Weld formation characteristics in hybrid ultra-high frequency pulse variable polarity GTAW of 2219-T87 high strength aluminum alloy

The weld formation characteristics in the hybrid ultra-high frequency pulse variable polarity gas tungsten arc welding (HPVP-GTAW) of 2219-T87 high strength aluminum alloy was investigated. The experimental results show that,under the condition of keeping the RMS of positive current approximately consistent (with permissible variation of ±5 A),welding with ultra-high frequency pulse square-wave current increased the ratio of weld depth to width by more than 20%,compared with the traditional variable polarity GTAW process. Pulse current frequency significantly affected the weld formation. Increasing the pulse current amplitude and decreasing the pulse current duty cycle within a certain range can remarkably enhance the weld penetration. The ratio of weld depth to width increased by more than 75% when the pulse current was 100 A and the pulse current duty cycle was 20%.