How to choose coatings? A overview
The following table gives an overview of coatings with their principal and additional functions.
| Principal functions | ||||
|---|---|---|---|---|
| Coating | Corrosion protection | Wear protection | Friction reduction | Additional function |
| Zinc | √ | - | ||
| Paint | √ | – | ||
| Tin | √ | Reduced contact corrosion | ||
| Zinc-iron | √ | – | ||
| Zinc-nickel | √ | – | ||
| Zinc flakes, Cr(VI)-free | √ | – | ||
| Chemical nickel | √ | √ | – | |
| Hard anodising (Al) | √ | √ | Current insulation | |
| Columnar thin dense chromium coating | √ | Corrosion protection,slight reduction in friction, reduced fretting corrosion | ||
| Columnar thin dense chromium coating plus mixed chromium oxide | √ | √ | √ | Additionally good corrosion protection |
| Microcracked thin dense chromium coating | √ | Slight corrosion protection, slight reduction in friction | ||
| Black oxide coating | √ | Improved running-in behaviour, reduced slippage damage, slight corrosion protection | ||
| Manganese phosphate | √ | Improved running-in behaviour, slight corrosion protection, emergency running lubrication | ||
| Zinc phosphate | √ | Temporary corrosion protection, protection against fretting corrosion, suitable for sliding seats | ||
| Copper | √ | Emergency running lubrication | ||
| Silver | √ | Emergency running lubrication | ||
| PTFE | √ | Protection against fretting corrosion, friction reduction | ||