SELGA-COAT® (Selective hard anodising)

SELGA-COAT® is a process for the selective electrolytic coating of aluminium alloys. Defined surface areas are processed in a targeted manner. Any parts of a component that do not need to be coated are covered in a special mechanism with an incorporated sealing system. By means of a storage tank an electrolyte is pumped into the device and it is applied between the free component surface and the mechanism's housing. The component's surface acts as an anode, the charge is the opposite of that of the mechanism's housing.

SELGA-COAT® layers, compared to conventionally produced coatings, have substantially improved properties, such as e.g.

  • excellent covering capacity
  • increased corrosion resistance
  • layer hardness values ranging between 300 and 500 HV
  • layer build-up, e.g. 12 μm in less than 1 min.
  • more regular microstructures
  • highly improved levelling capacity
  • substantially less surface roughening
  • considerably cleaner surface quality

Generally, no further machining is required.

SELGA-COAT® is well-suited for the coating of wrought, cast and die-cast aluminium alloys.

SELGA-COAT® has proven outstandingly successful for the selective coating of automotive parts, such as:

  • wheel hubs and bearings
  •  valves (e.g. injection pumps)
  • engine pistons (diesel, otto)
  • valve pistons (automatic transmission)
  • components for brake systems
  • clutch components
  • pump housings (power steering)
  • sandwich plates (automatic transmission)

All technical values published here are subject to the test conditions specified. We therefore emphasise 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.