Pre-copper
The product is then immersed in a copper sulphate solution, where a few atomic layers of copper become separated through the charge exchange process, making the surface more conductive and preventing the electroless nickel coating from fusing.
Polished copper
The high-gloss copper layer is 20-30µm thick and ductile, which means it balances out the different expansion coefficients between metal and plastic.
Semi polished / polished nickel
A double layer of nickel is deposited for corrosion purposes and in order to compensate for tensions. The nickel layer is high-gloss and hard enough to be scratch-resistant.
Matt nickel / aluminium design
The nickel depositing process is briefly interrupted by the static distribution of finely dispersed organic substances in the cathode film. Through this surface disturbance, the directed light reflection of the initially shiny coating appears as a diffuse reflection. A thin chrome layer with a thickness of approx. 0.3µm is then deposited on the matt nickel.
Cracked nickel
To improve corrosion protection, an approx. 1-2µm thick, dynamic nickel layer is deposited on the polished nickel layer. As a result of the additional tensions, this cracked nickel layer breaks up during the subsequent polished chrome plating process together with the chrome layer, forming micro-cracked layers of chrome. Cracked nickel is used mainly in exterior automotive parts.
Polished chrome plating
Polished chrome plating takes place in very thin layers of 0.3-0.8µm.
The properties of the galvanic nickel base are key to the quality of the chrome plating.
After the chrome plating and drying process, the product is removed, checked and packaged. In addition to the usual visual inspection criteria, including degree of gloss, pores, scratches, stains, roughness, flowlines, welding seams and faulty coatings, we carry out the following tests:
- Layer thickness measurement using X-ray
- Thermal shock test compliant to DIN 53496
- CASS test compliant to DIN 50021
- Temperature resistance
- Adhesion tests (cross cut test, tape test)
- Dimensional stability
- STEP test (coulometric measurement)