电弧超声的激发及其特性研究

为了探索电弧在焊接过程自动控制、改善焊接接头质量等方面应用的新途径，提出以电弧自身作为可控的“超声发射源”的工作原理。在常规弧焊回路中采用了连续波和脉冲敲击式等不同的激励方式获得电弧超声信号。记录了电弧超声的频率、幅度、相移特性，初步估算了电弧超声声速。发现了电弧超声的若干“谐振频段”并对电弧频率响应的选择性现象进行了初步分析。试验结果表明，在弧焊过程中作为“产热机构”的电弧同时也可以作为“超声发射机构”，从而为开拓有关应用提供了可能性。

Study of arc-ultrasonic excitation and its characteristics

In order to study the potential application for improving the crystallization of molten metal and for automatic seam tracking by using the welding arc, a working principle of the arc excited ultrasonic emission was introduced. For arc ultrasonic excitation, both the continuous and the pulse signal was separately applied to the test system including a conventional arc welding circuit. The spectrum, amplitude, phase shift and the acoustic velocity of the arc ultrasonic were detected and recorded in the welding process. The acoustic resonant phenomenon shows the selective frequency response of the arc ultrasonic. It may be significant for the manufacturing and the material engineering that arc or plasma could function not only as a thermal source, but also as a mechanism of the ultrasonic emission.