Phase composition, microstructure and mechanical properties of ZrC coatings produced by chemical vapor deposition

摘要

We report results on stoichiometric and non-stoichiometric ZrC coatings produced on graphite substrates by chemical vapor deposition (CVD) in the ZrCl_4-CH_4-Ar system. The phase composition, microstructure and mechanical properties of both (ZrC and ZrC_(0.85)) coatings were studied. X-ray diffraction (XRD) confirmed the formation of cubic ZrC. A strong (200) texture normal to the substrate surface was observed in both coatings which were confirmed by scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) showed ZrC to be the main phase in both coatings with ~5.5 mol% ZrO_2 minor phase. In stoichiometric ZrC coating, both Young's modulus (312 ± 9 GPa) and hardness (25 ± 3.1 GPa) were higher compared to the non-stoichiometric ZrC_(0.85) coating.