The complete guide to dielectric coating for EV battery assemblies: TiZr passivation

Why is metal pre-treatment the key to the dielectric coating process?  

The titanium zirconium passivation (TiZr) is a chrome-free conversion coating that is applied to aluminium components. Through this process, the natural oxide layer is replaced with a stable, chemically modified ‘shield’ layer. 

This series of articles discusses some of the key challenges that need to be overcome to deliver a satisfactory dielectric coating solution.

                                                                                      The process of TiZr-passivation

The pre-treatment process removes surface dirt, oils, contamination, and the natural oxide layer and replaces it with a thin (approx. 20nm) stable Titanium/ Zirconium conversion layer. This results in a firm foundation for dielectric coating, providing long-term durability. 

Pre-treating the aluminium results in additional protection against corrosion, a significant factor for environments where the aluminium component may be exposed to moisture, chemicals, or high temperatures. 

Check out the video on how Dr. Nick Welton, Technical Manager at Powdertech, is using XRF equipment, Dyne inks, and UV-Fluorescence to measure metal surface cleanliness before and after TiZr- passivation. 

Common surface defects affecting dielectric coating performance. 

Metal pre-treatment: A key step towards achieving stated properties in technical data sheets. 

To deliver the design coating properties as stated on technical data sheets, like required insulation resistance, corrosion resistance, and any mechanical properties, you need to have a high-performance pre-treatment system to minimise defects to deliver a dielectric coating system that satisfies your specification requirements as mentioned in technical data sheets. 

Partner with Powdertech  

Over the years, Powdertech has supported major UK OEMs and Tier 1 suppliers with their dielectric coating projects for EVs, helping them optimise their coatings through upfront dielectric testing.   

If you are developing a component that requires a reliable dielectric coating solution, don’t wait for issues to surface during production; act early on. 

Contact Powdertech to see how they can support your dielectric coating project.