New route to synthesize ZrB2 coatings by reactive chemical vapor deposition method using Zr-BCl3-H-2-Ar reagents

摘要

A ZrB2 coating was deposited for the first time from a Zr-BCl3-H-2-Ar system by reactive chemical vapor deposition (RCVD) technique under a low pressure condition, and the effects of temperature and BCl3 and H-2 fluxes on the RCVD of ZrB2 were systemically evaluated. The temperature mainly affected the deposition rate, morphology, and infiltration ability of the coating and the conversion rate of ZrB2 particles. The reaction rate and the nucleation and growth of ZrB2 particles significantly varied with BCl3 flux. The H-2 flux affected the nucleation, growth, and conversion rate of ZrB2. A dense and smooth ZrB2 coating was deposited at 1273 K, and the BCl3 and H-2 fluxes were 80 mL/min and 150 mL/min, respectively. The deposition mechanism was elucidated from the experimental conditions. The ZrB2 deposition was controlled by surface reaction kinetics at low temperatures and by diffusion at high temperatures.