常压化学气相沉积ZrO_2涂层的显微结构与微观力学性能

Microstructure and micro-mechanical properties of zirconia coating by atmospheric pressure chemical vapor deposition

采用ZrCl 4-CO 2-H 2-Ar体系，于900~1500℃下用常压化学气相沉积法（APCVD）在C/C-SiC和C/C-ZrC基体上分别制备ZrO 2涂层。采用X射线衍射分析仪（XRD）和扫描电镜（SEM）分别分析ZrO 2涂层的相组成和形貌特征。利用微/纳米力学综合测试仪测量涂层的微观力学性能及与底层的界面结合力。结果表明：在900、1150、1300和1500℃这4种温度下制备的ZrO 2涂层均为单斜相；随着沉积温度的升高，ZrO 2涂层表面形貌由小颗粒堆积态向大尺寸多晶转变，涂层厚度逐渐增加。化学气相沉积ZrO 2涂层硬度为1026.712HV，略低于电子束物理气相沉积ZrO 2涂层的硬度；ZrO 2涂层与C/C-SiC基体之间的结合强度高于ZrO 2涂层与C/C-ZrC基体之间的结合强度。扫描电镜观察显示：C/C-SiC基体ZrO 2涂层划痕表面光滑，而C/C-ZrC基体ZrO 2涂层划痕表面粗糙。

Zirconia coatings were deposited on C/C-SiC and C/C-ZrC substrates by atmospheric pressure chemical vapor deposition （APCVD） with ZrCl4-CO2-H2-Ar system at 900？1 500℃, respectively. The phase composition and surface morphologies of the ZrO 2 coatings were investigated by X-ray diffractometry （XRD） and scanning electron microscopy （SEM）, respectively. The micro-mechanical properties of the coatings and the bonding strength between the coatings and substrates were tested by the micro/nano comprehensive mechanical property test instrument. The results show that the ZrO2 coatings prepared at four different temperatures of 900, 1 150, 1 300 and 1 500 ℃ are monoclinic phase ZiO2. The surface morphology of the coating changes from accumulation of small grains to polycrystal with large size as the temperature increases, at the same time the thickness of the coatings increases. The microhardness of the coating is 1 026.712HV, which is a little lower than that of ZrO2 coating prepared by electron beam physical vapor deposition and the ZrO 2 coating combines better with C/C-SiC substrate than that with C/C-ZrC substrate. The results of SEM show that the surface scratch of ZrO 2 coatings on C/C-SiC substrate is smooth while that is rough on C/C-ZrC substrate.