Microstructure, mechanical and tribological properties of TaCN composite films

Tantalum and carbon nitride films, with varied power of the carbon target were synthesised by multi-target magnetron sputtering. The microstructure, mechanical and tribological properties of TaCN films were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, atomic force microscopy, scanning electron microscopy, nano-indentation, nano-scratch, and a high temperature ball-on-disc tribometer. X-ray diffraction reveals that these films exhibit face centred cubic and base centred orthorhombic crystal structures, regardless of the power of the carbon target. At 50 W, the hardness, critical loads for cohesive failure (Lc(1)) and critical loads for adhesive failure (Lc(2)) of these films reach a maximum, 286 GPa, 452 N and 81 N, respectively, while at 80 W, the lowest average friction coefficient and wear rate of TaCN films are obtained, measured as 036 and 291x10(-7) mm(2) N-1, respectively.