2219-T87高强铝合金HPVP-GTAW焊缝成形参数

采用复合超高频脉冲方波变极性钨极氩弧焊技术（HPVP-GTAW，Hybrid ultrahigh frequency Pulse Variable Polarity Gas Tungsten Arc Welding）完成了2219-T87高强铝合金平板堆焊试验，研究了HPVP-GTAW工艺脉冲电流参数对焊缝成形参数的影响规律.结果表明，与常规变极性钨极氩弧焊（VP-GTAW）工艺相比，HPVP-GTAW工艺有利于增加焊缝熔深，提高焊缝深宽比；调节脉冲电流参数，将对焊缝成形行为产生显著影响.在正极性期间平均电流恒定的条件下，随着脉冲电流频率的增加，焊缝熔深、深宽比整体提高，60 kHz条件下深宽比增加了60%；适当增大脉冲峰值电流与基值电流的比值，焊缝深宽比有所增大；与占空比50%和80%条件相比，20%条件下焊缝深宽比最高，且随着峰值电流与基值电流比值的提高，其焊缝深宽比增幅最为明显.

Weld appearance of 2219- T 87 high strength aluminum alloy produced by HPVP-GTAW process

Based on hybrid ultrahigh frequency pulse variable polarity gas tungsten arc welding (HPVP-GTAW) surfacing process for 2219-T87 high strength aluminum alloy, the effect of pulse current parameters on weld appearance was analyzed. Experimental results show that the weld penetration and weld depth to width was improved significantly by HPVP-GTAW process, compared with the conventional VP-GTAW process. The weld appearance was changed obviously when the pulse current parameters were adjusted. With constant average current at positive polarity duration, the weld penetration and weld depth to width was overall improved with the increase of the pulse frequency, and weld depth to width increased by 60% when the pulse frequency reached up to 60 kHz. Weld depth to width was improved with the increasing of the ratio of the pulse peak current and base current. Weld depth to width was the highest with 20% duty cycle and improved most significantly with the increase pulse current ratio compared with the duty cycle of 50% and 80%.