Spot welding of aluminum plate with energy storage welding machine

What is spot welding?

Spot welding has a high production rate. It is possible to weld multiple metals at a go. It does not generate a high heat output meaning the base metal is not subjected to high heat. The cost of installation is high compared to other welding processes. This type of welding is vulnerable to metal deformation.

How to spot weld aluminum?

Place the two steel sheets on the points where you want to apply the spot weld. Slide the sheets in between the two electrodes of the spot welder. Ensure the two steel sheets are the ones that are in direct contact with the electrodes. By This spot welding, these two aluminum sheets stick with as tap joins. Spot welding has a high production rate.

How do weld spots work?

The amount of overlap and the distance between the weld spots depend on the electrical conductivity of the work material, i.e., the distance chosen between the weld spots increases with increasing electrical conductivity. The diameters of weld spot and weld nugget depend on the electrode geometry and on the number of weld spots.

Is spot welding 100% pure aluminum possible?

Technically speaking, spot welding 100% pure aluminum is nearly impossible. A thin layer of aluminum oxide forms on the surface of the aluminum. This layer has a very high electrical resistance. Since spot welding relies on resistance heating, the layer of aluminum oxide makes it almost impossible.

Why is spot welding difficult?

Since spot welding relies on resistance heating, the layer of aluminum oxide makes it almost impossible. The high electrical resistance of the layer means a higher current is needed. Spot welding aluminum is something many people have problems with. Spot welders are usually incapable of penetrating aluminum due to the formation of aluminum oxide.

Why is aluminium suitable for spot welding?

The high affinity of aluminium for oxygen, which causes metallic blank aluminium to be covered at once with a thin, dense and tightly adhering oxide film, has a major effect on the suitability of aluminium for spot welding. The oxide film has a high thermal stability and a melting temperature of over 2,000°C and is a non-conductor of electricity.