It is reported that a dual-layer carbon film on SiC wafer is prepared using carbide-derived carbon (CDC) process with subsequent chemical vapor deposition (CVD). The dual-layer film includes a sub-layer of CDC and a top layer of CVD, which are prepared by chlorination of SiC and pyrolysis of CCl4 at high temperature respectively. The CDC and CVD layers are mainly amorphous. And similar dispersion effects are observed in the Raman spectra, although the D-band position of the CVD layer shifts to higher wavenumber (~ 1354 cm− 1) than that of the CDC layer (~ 1337 cm− 1). Surface chemistry analysis suggests that the unstable chemical bonds, mainly C―Cl, as well as dangling bonds in the CDC layer play an important role in promoting the nucleation of CVD carbon. The surface morphology evolvement from SiC wafer to CDC layer and to dual-layer film is investigated by atomic force microscopy [AFM] and field emission scanning electronic microscopy [FESEM]. The nanoporous surface formed in the CDC process is favorable for capturing carbon species from the gas phase and can act as a “seedbed” for the nucleation and growth of CVD layer. The primary tribological study indicates that the dual-layer film shows great advantages in friction reduction and wear resistance with comparison to SiC and CDC layer, suggesting its potential in lubrication for SiC-based moving components.
• The dual-layer carbon film is prepared using CDC process with subsequent CVD method.
• The surface of the CDC layer is highly porous in structure and chemically active.
• The CDC layer acts as a seedbed layer for the nucleation and growth of the CVD layer.
• The dual-layer film is tested as an effective lubricating coating for SiC components.
Source: Surface and Coatings Technology