| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 701808 | Diamond and Related Materials | 2015 | 9 Pages |
•(Cr, N)-DLC/DLC multilayer films were deposited by FCVA combined with DCVA.•The (Cr, N)-DLC layer consists of amorphous phase and nano-crystals.•Co-doping could relieve DLC film's residual compressive stress effectively.•The multilayers' toughness can be tuned by varying sp3 content in DLC layer.•The multilayer films exhibited good wear resistance and high adhesion to YG8.
Alternating multilayer diamond-like carbon (DLC) films [(Cr, N)-DLC/DLC] with different sp3 contents in DLC layer have been prepared on YG8 (WC-Co) substrates by FCVA combined with DCVA technique. The structure was investigated by scanning electron microscopy and transmission electron microscopy. Chemical bonding was studied by Raman spectroscopy and X-ray photoelectron spectroscopy. Mechanical and tribological properties including residual stress, hardness, adhesion strength and wear resistance were evaluated by film stress tester, nanoindenter, scratch tester, ball-on-disk tribometer and surface profiler. The results showed that (Cr, N)-DLC layer had the composite structure of amorphous phase as base interspersed with a small amount of nano-crystals. The co-doping of Cr and N into DLC reduced the film's residual stress from − 1.62 GPa to − 0.99 GPa. For monolayer DLC, both the sp3 content and residual stress decreased as the substrate's bias voltage increased in the range of − 100 V to − 600 V. And the decrease of sp3 content contributed to an increase of the (Cr, N)-DLC/DLC films' toughness. In addition, the multilayer films presented good adhesion strength on YG8 substrates. The wear rates of all multilayer films belonged to the order of magnitude of 10− 7 mm3/Nm.Prime novelty statementMultilayer films consisting of DLC and DLC co-doped with metal and nonmetal atoms [(Cr, N)-DLC/DLC multilayer films] have been prepared by FCVA combined with DCVA technique and investigated systematically. The composite structure of the (Cr, N)-DLC layer is based on amorphous phase and contains a small number of nano-crystalline compounds of chromium.
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