Caption of photo: Housing for spot welding guns; in the front, on the right once passivated with chromium-free MAGPASS-COAT®, in the background
to the left uncoated piece and with chrome-free passivated layer plus powder coating, respectively. (Photo: C&C Bark GmbH)
MAGPASS-COAT® is a process for the chrome-free passivation of magnesium-based materials.
Coating with MAGPASS-COAT® is carried out, for instance, using immersion bath method. The workpiece is immersed in a chrome-free, inorganic and aquaeous passivation solution and it then develops a conversion layer on the workpiece surface. The conversion layer consists of oxides of the passivation solution and the base material. It is electrically conductive and it acts as an intermediate layer for following treatments like paintwork or gluing.