DLC Carbon

The properties of SilCor® DLC

The special diamond-like carbon SilCor® DLC shows a variety of superior properties which significantly increase the performance of machine components and tools. The wear resistant and friction lowering coating consists - simply spoken - of diamonds of nanometer size embedded in graphitic phases. This nano-structure has led to the commonly used expression "diamond-like carbon" or DLC.

The coatings are - in contrast to the well-known PVD coatings - completely smooth and dense. These are the striking properties of the coatings:

  • Diamond-like carbon SilCor® shows a superior surface quality - there is no increase of the roughness due to the coating. The rms self-roughness of a 2µ film is about 10nm.
  • DLC shows a very high corrosion resistance against salts, acids and leaches - none of these chemicals harm the coating.
  • The typical thickness of diamond-like carbon is 2µ. In special cases it can be lower (down to 10nm) or higher (up to 5µ).
  • The universal hardness is in the range between 10 GPa and 35 GPa (equivalent to about 1000 to 3500 HV). It can be adjusted by the process parameters.
  • SilCor® DLC films show a built-in stress increasing with hardness up to 1,5 MPa.
  • The elastic part of deformation amounts up to 90% - the deformation of the film due to a Vickers diamond practically “vanishes” if the diamond is removed. Sheet metal coated with DLC can be bended without destroying the film.
  • The coefficient of friction against dry steel is typically 0.15 (depending on load, roughness etc.). Coating both partners of friction with DLC, the value can be lowered to 0.04.
  • Diamond-like carbon shows an excellent adhesion to all clean surfaces. The critical load is substrate-dependent.
  • SilCor® DLC can withstand temperatures up to 350 degree Celsius under ambient air without changing its properties.

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