Superhard nanocrystalline composite materials: The TiN/Si3N4 system

Abstract

Thin films of novel superhard composite materials consisting of TiN nanocrystals in an amorphous Si3N4 matrix have been prepared by means of plasma chemical vapor deposition. The films show a high Vickers hardness of 5000 kg/mm2 and elastic modulus of ≳500 GPa, and they are resistant against oxidation in air up to ≥800 °C. The theoretical background of these unusual properties are briefly discussed and practical rules suggested according to which similar properties should be expected for composites of other ternary systems.