不同脉冲频率条件下2219-T87高强铝合金焊缝成形行为

Weld appearance of 2219-T87 high strength aluminum alloy at different pulse frequency

采用复合超高频脉冲方波变极性钨极氩弧焊接技术完成了2219-T87高强铝合金平板堆焊试验,分析了脉冲电流频率对焊缝成形特征的影响及其规律.结果表明,脉冲电流频率对电弧特性及熔池流动行为有较大影响,造成焊缝熔宽、熔深及熔透率出现显著变化.脉冲频率f H<60 kHz时,焊缝熔宽、熔深随脉冲频率的增加而增大,熔透率在f H<35 kHz时基本保持不变,在f H>35 kHz时出现显著提升,较常规变极性氩弧焊(VP-GTAW)至少提高了34%;当脉冲频率达到60 kHz时,焊缝熔透率达到最大,较VP-GTAW提高了约60%;脉冲频率f H>65 kHz时,熔宽、熔深及熔透率呈现回落趋势.

Based on hybrid ultrahigh frequency pulse variable polarity gas tungsten arc welding process of 2219-T87 high strength aluminum alloy,the effect of pulse frequency on weld appearance was analyzed.Experimental results show that the pulse frequency has a great impact on arc characteristics and the molten pool flow behavior,which makes significant changes in the weld width,depth and penetration.When the pulse frequency f H is less than 60 kHz,the weld width and depth increase with the increase of pulse frequency.The weld penetration is hardly changed with f H < 35 kHz,while it is considerably improved by at least 34% compared with the conventional variable polarity GTAW process when f H > 35 kHz.When the pulse frequency reached up to 60 kHz,the weld penetration significantly increases by 60% compared with the conventional variable polarity GTAW process.When the pulse frequency f H > 65 kHz,the weld width,depth and penetration presented show the downward trend.