交流TIG焊接电弧两极能量的分布特征

Characteristic of energy distribution at anode and cathode on AC TIG welding arc

通过发射光谱分析法和数学模型的应用,深入认识了交流TIG电弧EN,EP两个时段不同比例时对铝合金焊接工艺的影响以及电弧正负两极现象和能量分布特征.通过动态观测交流TIG焊接电弧全周期内的发射谱线,运用Stark展宽效应计算并获得了电子密度的时域特征;通过数学模型定量地分析了交流TIG焊接电弧正负两极不同的能量特征;通过分别观测EN,EP时段Ar,Al和O三种谱线的光谱特征,进一步认识了交流TIG电弧正负两极不同的发射机理和EP时段的阴极清理效果对焊缝成形尺寸的影响.结果表明,在交流TIG电弧中,EP时段的增加有助于焊接工艺与焊缝成形的质量.

During AC TIG welding of aluminum alloy,the physical phenomena of welding arc plasma at electrode negative(EN) and electrode positive(EP) periods and the characteristic of energy distribution at anode and cathode were investigated by observing the spectrum and founding the mathematical models.Furthermore, cathodic cleaning effect increases with the percentage of electrode positive.The dependence of electron density on time in the whole cycle is obtained with the theory of spectral line Stark broadening,and the characteristic of energy distribution is analyzed through the mathematical models.The mechanism of emitting electrons,cathodic cleaning and the quality of weld is better understood by observing the spectrum of argon,aluminum and oxygen respectively during EN and EP periods.