化学气相沉积ZrO_2涂层的表面微观形貌演变

Surface morphology evolution of ZrO_2 coatings by chemical vapor deposition

采用ZrCl4-CO2-H2-Ar体系,在不同温度或氢气流量条件下采用常压化学气相沉积法(APCVD)通过不同沉积流程在C/C样品表面制备ZrO2涂层。用X射线衍射分析仪(XRD)和扫描电镜(SEM)分析涂层的物相组成和形貌特征。结果表明:随沉积温度升高,ZrO2涂层表面形貌由小颗粒堆积态向大尺寸多晶转变;氢气流量为0时,只在局部区域出现了少量ZrO2,当氢气流量为400mL/min时,ZrO2涂层晶粒尺寸较大且晶体学平面特征最明显;在氢气流量为800mL/min时沉积出现了副产物ZrC与C;在氢气流量为1600mL/min时,出现沉积副产物ZrC;连续沉积时,得到的ZrO2涂层为山峰状形貌。

Zirconia（ZrO2） coatings were deposited on C/C samples by atmospheric pressure chemical vapor deposition （APCVD） from ZrCla-CO2-H2-mr system with different parameters. The phase composition and surface morphologies of the ZrO2 coatings were investigated by X-ray diffractometry （XRD） and scanning electronic microscopy （SEM）. The experimental results show that the surface morphology of the coating changes from accumulation of small grains to polycrystals with large size as the temperature increases. Only a little ZrO2 is found in part of the sample surface when prepared with no hydrogen, and the ZrO2 crystals are larger and have obvious characteristic of crystallographic plane when the hydrogen flow rate is 400 mL/min; the byproduct of C and ZrC is obtained when the hydrogen flow rate is 800 mL/min, and the byproduct of ZrC are obtained when the hydrogen flow rate is 1 600 mL/min. The surface morphology of ZrO2 coatings looks like mountain-peak when deposited constantly.