Example of use (automotive)

Coating of pistons with OXIDUR GST

Partial surface treatment of engine pistons to protect against wear and corrosion: treatment in closed system using GST (Gramm Selective Technology) with high accuracy and savings in chemicals.



  • OXIDUR HA layer providing high resistance to wear, heat and corrosion
  • Layer formed by conversion of the metal (aluminium) into ceramics (aluminium oxide), eliminating adhesion problems
  • Hard layer, 300 - 500 Hv
  • Rapid build-up
  • Standard roughness: 1,5–2,0. between 0.5 and 0.8 Ra possible
  • GST plant design goes back 15 years
  • Plant requires approx. 1/10 of the space of conventional plating equipment
  • Plating process can be integrated into manufacturing flow
  • High safety level for workers and plant (vacuum design and closed cycles)
  • Closed system avoids open baths and need for extractors/waste management
  • Process available as contract plating or operator partnership on site

more examples of use

Coating material: OXIDUR HA 15 - 20 µm
Substrate: AlMgSi aluminium alloys
selective GST (Gramm Selective Technology)
coating possible, e.g. band at ignition end,
1st groove, band below this, base,
2nd groove, band below this, piston shaft, pin-hole.