Structural characteristics and tribological properties of TiAlCr(Si)CN nanocomposite films coated on the SPK 1.2080 tool steel using PVD technique

Abstract

In the present work, structural characteristics and tribological properties of the Ti-Al-Cr-(Si)-C-N nanocomposite films coated on the SPK 1.2080 tool steel byPVD technique have been investigated. The PVD coating process was carried out using Ti (Si) Al and CrAl cathodes at 150 A current, 40 V bias and (Ar)0.1(CH4)0.45(N2)0.45 gas mixture for 50 min. Evaluations were conducted by OM, FESEM, AFM, XRD, nano and micro-indenters, and pin-on-disk tribometer. The uniform films with an about 2.5 μm thickness, and 11.7 and 9.5 nm crystallite size values were respectively formed on the Ti-Al-Cr-C-N and Ti-Al-Cr-(Si)-C-N coated specimens. Surface hardness of the Ti-Al-Cr-C-N and Ti-Al-Cr-Si-C-N-coated samples was respectively obtained 8.7 and 10.8 GPa compared to 2.16 GPa for the un-coated substrate. Roughness (RMS), reduced modulus (E) and H/E ratio related to the Si-incorporated film were respectively determined 4.6 nm, 477 GPa and 0.081 than that of the 9.7 nm, 364 GPa and 0.075 for the Si-emptied film. Tribological properties were significantly enhanced by both the films particular the Si-incorporated kind.