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

We report results on stoichiometric and non-stoichiometric ZrC coatings produced on graphite substrates by chemical vapor deposition (CVD) in the ZrCl4-CH4-Ar system. The phase composition, microstructure and mechanical properties of both (ZrC and ZrC0.85) 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 similar to 5.5 mol% ZrO2 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 ZrC0.85 coating. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.