Plansee, in cooperation with Oerlikon Surface Solutions AG and Vienna University of Technology’s (TU Wien) Institute of Materials Science Technology, has revealed the findings of a study to investigate the fracture toughness of Ti-Si-N thin films. Nanocomposite thin films are a kind of hard coating which offers attractive mechanical properties such as high hardness and strength values.
The self-organising nanostructures are typically made up of a nanocrystalline transition metal nitride, embedded in an amorphous, covalent nitride phase. One of the systems most frequently investigated in this context is titanium silicon nitride (Ti-Si-N). Although the considerable hardness of these types of coatings has already been discussed extensively in numerous studies, Plansee reported that little is known about their fracture toughness, i.e. the resistance of the material against the propagation of existing cracks.
The study established quantitative fracture toughness values for Ti-Si-N coatings on the basis of micromechanical trials under a scanning electron microscope. The authors demonstrated the dependence of fracture toughness on the phase composition and microstructure of Ti-Si-N coatings produced using special Ti-TiSi2 targets from Plansee Composite Materials GmbH.
Plansee manufactures powder metallurgical Ti-Si targets for a wide range of the compounds for which there is a demand. It is thus possible to control the properties of the coatings deposited in the PVD process by an appropriate silicon content in the targets (up to 30 at % Si) and in the coatings themselves.
The authors M Bartosik, R Hahn, Z L Zhang, I Ivanov, M Arndt, P Polcik and P H Mayrhofer have released details of the research findings in a paper entitled “Fracture toughness of Ti-Si-N thin films” in the International Journal of Refractory Metals and Hard Materials.