Structural characteristics and tribological properties of TiAlCr(Si)CN nanocomposite films coated on the SPK ۱.۲۰۸۰ tool steel using PVD technique

In the present work, structural characteristics and tribological properties of the Ti-Al-Cr-(Si)-C-N nanocomposite films coated on the SPK ۱.۲۰۸۰ tool steel byPVD technique have been investigated. The PVD coating process was carried out using Ti (Si) Al and CrAl cathodes at ۱۵۰ A current, ۴۰ V bias and (Ar)۰.۱(CH۴)۰.۴۵(N۲)۰.۴۵ gas mixture for ۵۰ min. Evaluations were conducted by OM, FESEM, AFM, XRD, nano and micro-indenters, and pin-on-disk tribometer. The uniform films with an about ۲.۵ μm thickness, and ۱۱.۷ and ۹.۵ 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 ۸.۷ and ۱۰.۸ GPa compared to ۲.۱۶ GPa for the un-coated substrate. Roughness (RMS), reduced modulus (E) and H/E ratio related to the Si-incorporated film were respectively determined ۴.۶ nm, ۴۷۷ GPa and ۰.۰۸۱ than that of the ۹.۷ nm, ۳۶۴ GPa and ۰.۰۷۵ for the Si-emptied film. Tribological properties were significantly enhanced by both the films particular the Si-incorporated kind.

Keywords:

tool steel , Ti-Al-Cr-(Si)-C-N , Microstructure , tribological behavior