알루미늄 합금의 아크 용접시 흑분 발생량에 미치는 영향인자에 관한 연구 = An experimental Study on factors for soot concentration during arc welding of aluminum alloy

다국어 초록 (Multilingual Abstract)

In case of welding aluminum alloy, specially of high percentage magnesium, fine soot is often observed around weld bead which looks charcoal powder sprayed around weld bead. Soot deteriorates weld bead appearance which leads to misunderstanding of poor weld quality. Removal of soot requires additional man power and cost while removal work causes respiratory disease. And soot degrades the adhesion strength between base metal and painting.
In this study first, variations of soot concentration are examined while magnesium contents of aluminum alloy base metal and filler wire are changed. Second, variations of soot concentration are examined while GMAW torch angle is changed to forehand, perpendcular and backhand position. Quantitative analysis such as weighing soot is not attempted but area of soot on the photo of aluminum weldment is measured through AutoCAD. In this study soot concentration is defined as the area of soot around weld bead.
Composition of soot is determined Al-Mg oxide by SEM analysis. Soot is concentrated around arc starting area and crater area while the soot concentration at the mid of weld bead is not high. The soot concentration is increased as magnesium content of aluminum alloy in base metal or filler wire is increased. Soot concentration is varied in sequence of backhand, perpendicular, and forehand position.