Different surface coatings are presented for the requirements as to corrosion resistance. A further advantage of some of the coatings is a reduction in friction, which achieves a significant improvement in sliding properties and lifetime when using slide bearings. In general, it is possible to provide these as chromium-VI-free variants and in numerous layer thicknesses.
Galvanic zinc coating with additional post-treatment (passivation without hexavalent chromium compound) is an excellent protection system against corrosion. The passivation is available in different colors such as blue, black, olive, transparent, and many more.
This is the classic chromium-VI-free alternative to yellow chromating; it stands out with its excellent corrosion resistance. Ready availability and attractive pricing round off this profile.
A zinc-flake coating is a layer consisting of zinc and aluminum flakes. It ensures a resistance of up to 720 hours in the salt spray test (DIN EN ISO 9227) with a 5% salt content. Thus, this coating is suitable for requirements of the uppermost levels of rust protection.
This is a coating of pure nickel with good corrosion resistance and high wear protection. As a rule, this coating is applied in several layers and is used for the utmost demands of our slide bearings.
Phosphatizing is a widely used treatment, in which a so-called conversion layer of firmly adhering metal phosphates is formed by a chemical reaction. Although this method offers only medium corrosion protection, it does extend advantages in friction reduction.
Burnishing is used to form a thin and black protective layer of mixed oxides on ferrous surfaces. This is exploited to reduce corrosion as well as to change color and reflectivity.
In order to avoid corrosion or contamination of the surfaces during transport or storage, it is best to utilize oily substances for preservation.
Powder coating is typically applied with housings or other pieces. It is a process in which an electrically conductive material is coated with powder paint in order to warrant good resistance to corrosion.