Friction-wear behaviors of cathodic arc ion plating AlTiN coatings at high temperatures

An cathodic arc ion plating AlTiN coating was prepared on a YT14 hard alloy. The surface-interface morphologies, the compositions of chemical elements and the phases were analyzed with using SEM (scanning electron microscopy), EDS (energy dispersive spectrometry) and XRD (X-ray diffraction), respectively. Additionally, the surface roughness and grain diameter were observed using AFM (atomic force microscopy). The COFs (coefficients of friction) and wear behaviors of the AlTiN coating were investigated using a high temperature tribological machine at high temperatures (700-900 °C), which were measured with a XM808P type PID temperature control instrument. The results show that the N content of the coating is fully released at high temperatures, and the mixed oxides of Al2O3 and TiO2 are formed, improving the wear resistance and lubricating effect of the AlTiN coating. The average COF of the AlTiN coating at 700 °C, 800 °C and 900 °C is 0.77, 0.65 and 0.57, respectively, showing good tribological properties, the wear mechanisms are primarily composed of oxidation wear and abrasive wear, accompanied with fatigue and adhesive wear.