Aluminum and aluminum alloy sheets can be welded by tungsten alternating current argon arc welding or tungsten pulse argon arc welding, and the equipment is complicated, which is not suitable for open-air operation.

2, resistance spot welding, seam welding,

Large welding current and high productivity. It is suitable for resistance collision welding of mass-produced parts and aluminum alloys. Generally, only plates with thickness less than 5 mm or bars with thickness less than 10 mm can be overlapped.

3, pulsed argon arc welding

The welding deformation and heat affected zone are small, especially suitable for thin plates.

4, low temperature flame welding

The third generation derivative liquefied gas spray gun can be used as a welding tool, and then welding can be carried out with low temperature aluminum welding wire. The commonly used welding tool is Viodin 303 low-temperature aluminum clad covered electrode, which is usually welded at 179.

Extended data:

If aluminum is welded by TIG welding, there are four kinds of tungsten materials for TIG welding: pure tungsten, thorium tungsten, cerium tungsten and zirconium tungsten. Pure tungsten electrode has high melting point and boiling point, and is not easy to melt and volatilize, but its electron emission ability is worse than thorium tungsten and cerium tungsten.

At present, the commonly used cerium tungsten electrode (brand WCe20) is made by adding cerium oxide (impurity ≤ 0. 1.8% ~ 2.2%) to pure tungsten. Cerium-tungsten electrode has the advantages of low electron work function, high chemical stability, high reliability of repeated arcing, high allowable current density, low burning loss rate and radioactivity elimination.

Preparation before welding:

1, groove treatment, unilateral groove 55, bilateral groove 35, to reduce the defect probability. Clean the impurities in the welding area, clean with stainless steel brush or acetone, and weld immediately after cleaning. The preheating temperature is controlled between 80 ~ 120℃, and the interlayer temperature is controlled between 60 ~ 100℃. Excessive temperature will increase the possibility of cracks.

2. With the increase of welding current, the wire feeding speed will increase accordingly. It is suggested to adopt a large welding current and a slow welding speed, and the welding gun angle is about 90. Too large or too small will cause welding defects.