HfC coatings were prepared on C/C composites by chemical vapor deposition (CVD) of HfCl4CCH4H2Ar system. The microstructure and mechanical properties of the prepared coatings were tested by X-ray diffraction (XRD), scanning electron microscopy (SEM) and ultra-nano indentation. Effect of deposition temperature on phase
Composition, deposition rate, microstructure and mechanical properties were investigated. The result shows all
The prepared coating exhibited an FCC HfC phase. As the temperature increases, the deposition rate increases. The preferential orientation of the HfC crystal changes from (220) to (200), and the coating structure changes from fine to coarse.
Columnar crystals. The hardness and modulus of the HfC coating ranged from 16-21 GPa and 247-282 GPa, respectively. At 1500 ° C, the most favorable hardness and modulus are 20.29 GPa and 282.34 GPa, respectively.