Sun Wei, Xiong Xiang, Li Xiaobin
State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, China.
J Nanosci Nanotechnol. 2011 Sep;11(9):8328-32. doi: 10.1166/jnn.2011.5106.
To settle the problem of low growth rate when prepare ZrO2 thermal barrier coating by Metalorganic CVD (MOCVD), a simple method was employed-atmospheric pressure CVD (APCVD). The paper firstly thermodynamic calculated the effect of O/Zr ratio and temperature on phase formation at various H/C ratios for ZrCl4-CO2-H2-Ar system. With temperature increment, the solid phase changes from C+ monoclinic ZrO2 to Monoclinic ZrO2 then to tetragonal ZrO2. With the increase of H/C ratio, the phase zone of C+ monoclinic ZrO2 expands. XRD and Raman spectrum were employed to measure phase structure of ZrO2 coating at different temperature. At 1300 degrees C, the coating contains a small amount tetragonal ZrO2 phase besides monoclinic phase; at 1100 degrees C, the coating is composed of monoclinic ZrO2 phase and a little C. The surface SEM images show the small grains evolve to polycrystals which have clear crystal form when raising temperature. The cross-section images show that dense ZrO2 column crystals arrange normal to the substrate.
为解决采用金属有机化学气相沉积（MOCVD）法制备ZrO2热障涂层时生长速率较低的问题，采用了一种简单的方法——常压化学气相沉积（APCVD）。本文首先对ZrCl4-CO2-H2-Ar体系在不同H/C比下，O/Zr比和温度对相形成的影响进行了热力学计算。随着温度升高，固相从C+单斜ZrO2转变为单斜ZrO2，然后转变为四方ZrO2。随着H/C比的增加，C+单斜ZrO2的相区扩大。采用X射线衍射（XRD）和拉曼光谱测量不同温度下ZrO2涂层的相结构。在1300℃时，涂层除单斜相外还含有少量四方ZrO2相；在1100℃时，涂层由单斜ZrO2相和少量C组成。表面扫描电子显微镜（SEM）图像显示，随着温度升高，小晶粒演变成具有清晰晶形的多晶体。横截面图像显示，致密的ZrO2柱状晶体垂直于基底排列。
