Titanium- and Tantalum-based CVD coatings

Since Iron and Cobalt catalyse graphite formation during the CVD diamond deposition, high temperature intermediate layers are developed, which inhibit graphite forming on steel or hard metal surfaces. A special surface microstructure of the intermediate layer alloys a good mechanical adhesion with the subsequently growing diamond layer.

In the temperature range from 500 °C to 1100 °C, CVD deposition of metallic Titanium or Tantalum layers and their carbides, nitrides or borides are possible.

Coating examples:

• TiNB-intermediate layer on X46Cr13 for optimal diamond adhesion.
• TiB₂ on graphene fibres for stabilization after Zirconium-melt infiltration.
• Ta on graphene to increase the chemical stability.

• Kütemeyer M., Helmreich T., Rosiwal S., Koch D.:
  Influence of zirconium-based alloys on manufacturing and mechanical properties of ultra high temperature ceramic matrix composites
  In: Advances in Applied Ceramics 117 (2018), p. 62-69
  ISSN: 1743-6753
  DOI: 10.1080/17436753.2018.1509810
• Kütemeyer M., Schomer L., Helmreich T., Rosiwal S., Koch D.:
  Fabrication of ultra high temperature ceramic matrix composites using a reactive melt infiltration process
  In: Journal of the European Ceramic Society 36 (2016), p. 3647-3655
  ISSN: 0955-2219
  DOI: 10.1016/j.jeurceramsoc.2016.04.039