BN/CN/Ti(N) Multilayer Coating for Tribological Applications

We have demonstrated growth of thin BN, CN and TiN films on several substrates (semi-insulating and highly doped silicon, cubic and hexagonal silicon carbide, sapphire, borane silicate, molybdenum, gallium nitride, diamond, and stainless steel). The deposited insulating BN thin layers mechanically hard (Knoop hardness values of ~ 3350 kg/mm²), uniform (rms roughness ~ 15.0 Å), very smooth surface (coefficient of friction of 0.34 is slightly lower than the value measured from stoichiometric TiN, a widely used hard coating) and porosity free materials. In terms of high temperature applications, BN films show good thermal stability up to 1000 °C after thermal vacuum annealing. The combined superior smoothness with respectable friction and hardness properties makes our BN material a good candidate for coating applications (including corrosive and high temperature environments).