Should be used welding aluminum welding electrodes  with the following characteristics:

1) to provide high current in a short time;

2) The current waveform of the best features of a slow rise slow down;

3) can precisely control the process parameters, and is not voltage fluctuations;

4) to provide price-shaped and saddle-shaped electrode pressure;

5) The head of the inertia and friction is small, the electrode with good mobility.

The current domestic use are mostly 300-600KVA DC pulse, frequency and phase secondary rectification welding machine, the individual to 1000KVA, all have these characteristics. There is also single-phase AC welding machine, but only in unimportant parts.

Aluminium welding electrode should be used for Class 1 the electrode alloy, spherical end, in order to facilitate solid nugget pressure and heat.

As the current density there is large and the oxide film, aluminum spot welding, it is prone to electrode adhesion. Electrode not only affects the appearance of the adhesive quality, but also reduced due to reduced current strength of the joint. This is subject to frequent trimming electrode. Finishing order of the electrode after each piece points welder and welding conditions, welded metal model, clean condition, with or without current waveform modulation, the electrode material and the cooling conditions and other factors. 5-10 points usually aluminum welding, spot welding LF6, LY12 when 25-30 points.

LF21 aluminum low intensity anti-permeability, ductility after welding better, no crack, usually fixed electrode pressure. Hard aluminum (such as LY11, LY12), super-hard aluminum (such as the LC4, LC5), high strength, ductility is poor, can easily crack, must adopt price-shaped curve of the pressure. But for thin pieces, using a large welding pressure or pulse with a slow cooling double-pulse heating, the crack is not inevitable.

Shaped by price pressure, the forging force behind a very important moment in power, usually 0-2 weeks. Forging force increases too soon (before the power failure), equivalent to increasing the welding pressure, will affect the heating, resulting in lower joint strength and volatility. Forging force increase is too late, the nugget has been formed during the cooling crystallization of crack, plus forging force have been. Sometimes in advance of forging force exerted on the power point, because the delayed action of electromagnetic valve, or pneumatic forging force is not caused by increased flow is slow, do not apply early enough to prevent cracking of the reason.