Structural and mechanical properties of TiC and Ti–Si–C films deposited by pulsed laser deposition

Abstract

TiC and Ti–Si–C films have been deposited by pulsed laser deposition at substrate temperatures ranging from room temperature to 600 °C onto (111) silicon wafers and 440C stainless steel substrates. X-ray diffraction, x-ray photoelectron spectroscopy, and electron microscopy were employed for structural and compositional evaluation of the films, and nano-indentation hardness testing and pin-on-disk wear tests were used to evaluate the mechanical and tribological properties. All the TiC films were highly crystalline except the one deposited at room temperature, whereas for the Ti–Si–C films the degree of crystallinity increased with temperature, ranging from amorphous for the room temperature deposit to about 50% crystalline at 600 °C. The hardness of the TiC films was relatively constant with deposition temperature at about 25 GPa, whereas the hardness of the Ti–Si–C films increased with deposition temperature from 11 to 33 GPa. The temperature dependence of the hardness is attributed to the degree of crystallinity and the extent of phase separation in the Ti–Si–C films. The wear test data showed good results for all films up to the tested limit of 10 000 cycles at 1 N load.