The effect of deposition temperature on microstructure and properties of thermal CVD TiN coatings

Coatings of TiN have been deposited by thermal CVD between 850 and 1050 °C and characterized with respect to their microstructure as well as mechanical and tribological properties. X-ray diffraction (XRD) analysis yields the formation of textured films, particularly at low deposition temperatures. It is shown that the coating hardness changes with the texture, where highly (2 1 1) oriented films exhibit a lower hardness compared to non-textured coatings. The wear resistance has been determined by dry sliding experiments against Al2O3 balls at 25 °C on both as-deposited and polished samples. Independent on the surface roughness, the smaller grain size of the textured films causes a higher toughness and results in a better wear resistance.