Resistance welding can be used to join electrically conductive materials together without the addition of any other material. In this process, large currents are passed by two opposing electrodes for a short period to the components to be joined. The transfer resistance at the contact zone leads to heating, further increasing the resistance, which then leads to the melting of the contact zone and the welding of the components.
The power source used can be both direct current (DC) and alternating current (AC) or the discharge from a capacitor (CD).
Capacitor pulse welding in particular can achieve very large currents (500 kA) in very short exposure times. This results in very low heat input, ensuring the minimum of distortion. In resistance welding with DC or AC current, the welding current is supplied by a transformer.
The small contact zone is produced by the shape of the electrodes during spot and seam welding.
In projection welding, the current concentration at the weld joint is achieved by impressing a weld projection onto the components.
With this technology, Eberle is able to join parts made of different materials and with different thicknesses with virtually no distortion in highly productive automated facilities.