Metal

DLC (diamond-like carbon) coatings – aluminium and steel

The project participants research the improvement of amorphous, hydrogenated carbon coatings (a-C:H coats) that reduce wear and rework on tools. They also facilitate substantial reduction of lubricants.

 

Summary

In aluminium and stainless steel processing, tools display extreme wear. This is caused by the tendency of aluminium and steel to deposit material on the tools' surfaces. The material accumulating on the tools can enter the further production process and thus impair in particular the surface quality of moulded parts. The necessary replacement and reconfiguration of the tools as well as the quantity of scrapped moulded parts cause high tool and rework costs.

Amorphous, hydrogenated carbon coatings (a-C:H coats), on the other hand, display an extremely low tendency to deposit material. Their use can thus contribute to reduction of wear, rework and use of lubricants. 

The project's aim was to improve the a-C:H coats deposited so far and the properties thereof (e.g. increasing adhesive strength and reducing material deposition on the tools).

Results:

  • Modification of ferrous substrates results in improved performance of the deposited amorphous, hydrogenated carbon coatings.
  • It was possible to increase the adhesive strength by a factor of four.
  • Shear-cutting tests showed a reduction in adhesive wear (accumulation of material on friction surfaces).
  • Heating the substrates before deposition of the coating improved coating adhesion by a factor of two.
  • Pretreatment of substrates followed by deposition of an a-C:H coat is a good approach for obtaining positive effects on adhesive wear of machining tools.
  • Thermal pretreatment of the substrates is a promising method of improving the adhesive strength of the a-C:H coats.
  • Integration of radiator heaters into the coating system facilitates use of only a single system for pretreatment and subsequent coat deposition.

Project Participants

Implementing Institution

Oerlikon Balzers VST GmbH & Co. KG

More Project Informations

Project title:  Verbundvorhaben 'In situ strukturierte DLC-Schichten für den reibungsminimierten und medienarmen Einsatz von Werkzeugen, Gleit- und Wälzlagern', Teilvorhaben 7: Strukturierte DLC-Schichten für die Verarbeitung von Aluminium und Edelstahl

Project number:  01RI05105

Project period:  2005 - 2008

Project region:  Germany (Baden-Württemberg)

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Source: German National Library of Science and Technology Hannover (TIB)