Aluminium passivation increases in EV production

Posted on Jun 30, 2025

Anochrome Technologies has seen significant growth in demand for its aluminum passivation system as the number of electric vehicles increases.

Aluminium has become the material of choice for many EV automotive manufacturers due to its lightweight properties and, therefore, its ability to extend vehicle range and counter heavy components such as batteries.

Hexavalent chrome pre-treatment has been the standard for aluminium for many decades, but these processes have come under pressure for environmental and health and safety reasons.

The first chrome-free pre-treatment processes started to appear in the marketplace about 20 years ago. Today, with almost two decades of operating experience, the performance of these chrome-free programmes is equivalent to the old hexavalent chrome products.

As the amount of aluminium used in EVs has increased, Anochrome Technologies has seen a marked move towards its chrome-free aluminium pre-treatment passivation system, Gardobond X4707.

Anochrome is one of just a small number of businesses offering Gardobond X4707 and has recently utilised the process for bumpers, brackets and components.

Mark Smith, Assistant General Manager at Anochrome Technologies, said: “Passivation with Gardobond is an ideal solution for aluminium within electric vehicles.

“The use of Gardobond X4707 materially improves the performance of the subsequently applied paints, lacquers and powder coats by adding a chemical conversion coating to the surface which enhances adhesion and corrosion resistance.

“The performance of Gardobond X series products for aluminium is not only as good as hexavalent chrome which it replaces – in many cases even better results are achieved, both in the real world and under laboratory conditions.”

Passivation is the spontaneous formation of a hard non-reactive surface film that inhibits corrosion. This layer is usually an oxide that is a few nanometres thick.

The product is easy to handle, requires less energy to apply, improves worker’s safety and uses less rinsing water due to a closed loop system.