铝合金LB-VPPA复合焊接热源特性

发布时间：2019-05-06 12:08

【摘要】：以Al-Mn系铝合金LB-VPPA(laser beam-variable polarity plasma arc)复合焊接热源特性为研究对象,采用Y4-S2型高速摄像仪和汉诺威焊接质量分析仪分别研究了LB-VPPA复合热源焊接过程中的电弧形态的变化、焊接电流、电压的特征信息.结果表明,激光对VPPA焊接电弧有吸引作用,并且与VPPA正、反极性作用机理不同.正极性阶段发现激光被压缩于VPPA电弧内部且作用于电弧根部,而反极性阶段在VPPA电弧上方会出现一个等离子体柱.VPPA焊电弧根部等离子体对激光的逆轫致辐射吸收,电弧因温度升高而膨胀导致其横截面积变大;同时引入激光为VPPA焊接电弧提供了大量自由电子,电流密度增加、导电性增强、电导率提高、电阻减小,导致电弧电压下降了约3~4 V.随着激光功率的增加,激光对VPPA电弧作用效果明显增强.
[Abstract]:The heat source characteristics of Al-Mn aluminum alloy LB-VPPA (laser beam-variable polarity plasma arc) composite welding) are studied. Using Y4-S2 high-speed camera and Hanover welding quality analyzer, the characteristics of arc shape, welding current and voltage during LB-VPPA hybrid heat source welding were studied respectively. The results show that laser has an attractive effect on VPPA welding arc, and the mechanism is different from that of VPPA positive and negative polarity. In the positive phase, it is found that the laser is compressed inside the VPPA arc and acts on the root of the arc, while a plasma column appears above the VPPA arc in the reverse polarity stage. The inverse Bremsstrahlung absorption of the laser by the plasma at the root of the arc is observed. Because of the increase of temperature, the arc expands and its cross-sectional area becomes larger. At the same time, the introduction of laser provides a large number of free electrons for the VPPA welding arc. The current density increases, the conductivity increases, the electrical conductivity increases, and the resistance decreases, resulting in a decrease of arc voltage by about 3 V. With the increase of laser power, the effect of laser on VPPA arc is obviously enhanced.
【作者单位】：内蒙古工业大学材料成型重点实验室;
【基金】：国家自然科学基金资助项目(51365032) 教育部新世纪优秀人才支持资助项目(NCET-10-0908)
【分类号】：TG457.14

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