PLASMA CHEMICAL COATING-KEPLA-COAT
BASICS
KEPLA-COAT® is a plasma chemical coating that improves aluminium and titanium alloys.
Coating takes place in a saline solution electrolyte. The workpiece is connected in series to an external source of electricity and acts as an anode. During anodization oxygen plasma discharges itself on the workpiece surface and briefly melts the surface thus forming 2 oxide ceramic layers that bond tightly with the outer metallic layer. A barrier layer with a thickness of about 100 nm constitutes the direct bond with the aluminium or titanium workpiece. Then come an oxide ceramic layer with low porosity density followed by one with high porosity density. This layer bond protects the aluminium and titanium against wear and corrosion and, thanks to its surface structure, it allows the absorption of lubricants as well as following workpiece treatments such as, for instance, paintwork or impregnation.
Coating takes place in a saline solution electrolyte. The workpiece is connected in series to an external source of electricity and acts as an anode. During anodization oxygen plasma discharges itself on the workpiece surface and briefly melts the surface thus forming 2 oxide ceramic layers that bond tightly with the outer metallic layer. A barrier layer with a thickness of about 100 nm constitutes the direct bond with the aluminium or titanium workpiece. Then come an oxide ceramic layer with low porosity density followed by one with high porosity density. This layer bond protects the aluminium and titanium against wear and corrosion and, thanks to its surface structure, it allows the absorption of lubricants as well as following workpiece treatments such as, for instance, paintwork or impregnation.
PROPERTIES
KEPLA-COAT® layers applied to aluminuim consist of up to 60 percent of corundum. The remaining layer components are mainly Al2O3 and boehmite. Depending on the alloy of the coated workpiece, KEPLA-COAT® can reach a thickness of up to 150 µm. The layer thickness of structural aluminium components usually ranges from 40 to 60 µm. KEPLA-COAT® provides not only excellent wear protection, but also perfect uniform layer, dimensional accuracy and hardness. KEPLA-COAT®-coated substrates show a much greater fatigue strength than substrates with similar layers. These layers can resist aggressive gases such as chlorine and boron trichloride and a layer thickness of 30 μm, for instance, shows a corrosion resistance of more than 3,000 hours in the salt fog test according to DIN EN ISO 9227. In addition, KEPLA-COAT® ensures extremely good anti-friction properties in combination with PTFE or other dry lubricants.
All technical values published here are subject to the test conditions specified. We therefore empasise that the applications and operating conditions, along with the end user’s practical experience, will ultimately determine the level of performance achieved by the coating and/or coating system.
