热处理对纳米氧化锆热障涂层热物性的影响

采用大气等离子喷涂(APS)在GH33基体上制备了氧化锆纳米结构涂层,运用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电镜(TEM)和拉曼光谱(RS)等分析手段对原料粉末和涂层的显微结构、相组成进行了观察和确定,分别利用激光脉冲技术测量了热处理前后涂层的热扩散率.实验结果表明,等离子喷涂氧化锆纳米涂层颗粒分布在65~110nm之间,大于原料粉末的40~70nm,涂层主要由亚稳四方相氧化锆组成.1050℃下热处理34h后,涂层的热扩散率从制备态的2.15×10^-3~275×10^-3cm²/s升高到2.65×10^-3~3.25×10^-3cm²/s.

Effect of thermal treatment on thermal diffusivity of nanostructured zirconia coating

Yttria partially stabilized nanostructured zirconia coatings were prepared by atmospheric plasma spraying (APS). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were applied to analyze the nanostructured coatings and that after heat-treatment. Thermal conductivity were also measured by laser pulsed diffraction method. It was found that the as-sprayed zirconia coating had an average grain size of 67nm, and mainly composed of metastable tetragonal phase, together with some monoclinic phase and tetragonal phase. The thermal diffusivity of the as-sprayed nanostructured zirconia coating was 2.15×10^-3~2.75×10^-3cm²/s between room temperature and 800℃, but 2.65×10^-3~3.25×10^-3cm²/s for the coating after heat treatment at 1050℃ for 34 hours.