Effects of Al concentrations on the microstructure and mechanical properties of Ti-Al-N films deposited by RF-ICPIS enhanced magnetron sputtering

Ti-Al-N films were deposited on Si (1 0 0) and mirror-polished stainless steel at 300 °C by RF-ICPIS enhanced magnetron sputtering technique. Focusing on the effects of Al concentrations on the microstructure and mechanical properties of Ti-Al-N films, the structure and the growth morphology were characterized by X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). Ti-Al-N films with highest Al contents of were deposited at total gas pressure of 1.0 Pa. XRD experiments exhibited that the Ti-Al-N films were f.c.c structure with diffraction peaks at 2θ = 37.1°, 43.5°, 63.2°, and 75.1°, respectively. The FWHM values of (1 1 1) diffraction peaks showed a decrease while the (2 2 0) diffraction peaks showed an increase trend with the increasing of Al concentrations. With the variation of total gas pressure from 0.5 to 1.5 Pa, the RMS values of Ti-Al-N films increased from 1.286 to 7.751 nm. The hardness of the Ti-Al-N films was in the range of 28.4-36.2 GPa while the friction coefficients were in the range of 0.339-0.732.