基于U-I图的铝/钢双脉冲MIG熔-钎焊稳定性评价及其MATLAB实现

Evaluation of welding stability of double pulse MIG weldingbrazing of aluminum to steel based on U-I graph and its realization in MATLAB

针对铝/钢双脉冲MIG熔-钎焊过程稳定性差的问题,提出一种基于U-I动态工作点轨迹集中性的焊接过程稳定性评价方法.该方法通过MATLAB定量计算U-I图面积来表示U-I动态工作点轨迹集中性,U-I图面积越小,表明U-I动态工作点轨迹越集中,焊接过程越稳定;反之,U-I图面积越大,U-I动态工作点轨迹越分散,焊接过程越不稳定.结果表明,利用该方法得到的不同电弧作用位置下焊接过程稳定性与其对应的焊接电压方差、电压概率密度分布和电弧形态稳定性分析结果具有一致性,故该方法是可靠的,且为铝/钢双脉冲MIG熔-钎焊稳定性评定提供了定量指导.

For the poor welding process stability in double pulse MIG welding-brazing of aluminum to steel,an evaluation method of welding process stability based on the concentration of tracks of U-I dynamic operating points was proposed. The concentration of tracks of U-I dynamic operating point is represented by the area of U-I diagram quantitatively computed by MATLAB in this method. The smaller the area of U-I diagram is,the more concentrated the U-I operating point tracks are,the more stable the welding process will be; otherwise,the greater the area of UI diagram is,the more dispersed the the U-I operating point tracks are,the more unstable the welding process will be. The results show that the welding process stability at different welding positions obtained by this method is consistent with the analyses of welding voltage variance,probability density distribution of welding voltage and arc profile stability. As a result,this approach is reliable and provides a quantitative guidance in welding process stability evaluation of double pulse MIG welding-brazing of aluminum to steel.