Select suitable resistance welding electrodes for hybrid electric vehicle battery pack

Aluminum plates are notoriously difficult to weld, and attempts often result in feed problems, weak welding, and defects such as pits or cracking. Automakers face production challenges every time they develop a new aluminum-intensive vehicle or hybrid battery pack.

Are they going to glue it together, are they going to use rivets, or are they going to use a very specialized resistance welding process?

Although spot welding has its advantages, it is important to select the right resistance welding electrode based on a thorough understanding of the material properties. The wrong electrode material can lead to many problems in the production line, one of which is the alloying of the electrode material with the workpiece. For example, this is common when welding galvanized sheet; You should not use electrode materials that will react to zinc.

In theory, spot-welded aluminum should be ideal for electrode materials such as tungsten because of its resistance to alloying. In addition, base metals are very conductive. However, it has such high thermal conductivity that the current has to be applied for too long, and the tungsten electrode becomes too hot. As a result, aluminum tends to melt.

Silver-tungsten electrodes, by contrast, are well suited to the nickel foils increasingly found in hybrid car battery packs. These alloys are a good choice because silver prevents alloying with nickel. In fact, it has been found to be more suitable than commonly used copper electrodes because of copper's tendency to deposit and create potential short circuits.

If you are currently considering using electrode materials for resistance spot welding applications and are interested in learning more about how to make the right choice,

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