Document Type: Research Paper
Malek-Ashtar University of Technology 83145-115, Isfahan, IR Iran.
Malek-Ashtar University of Technology
Islamic Azad University 81595-158, Isfahan, IR Iran.
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.