利用大气等离子喷涂制备了ZrO2涂层,采用扫描电子显微镜结合图像分析的方法对涂层的显微结构特征(总气孔率和大气率)进行了量化表征.同时利用扫描电子显微镜附带X射线扫描成像对涂层内部的微裂纹和大的分隔裂纹的三维分布进行了表征.据此建立了ZrO2涂层显微结构与热导率之间的关系.室温下,涂层N2的热导率较N1的低,因为涂层N2内气孔和微裂纹数较多；在1000℃,由于微裂纹的烧结作用导致热导率增大,所以涂层N2的热导率较N1反而高.高温下,涂层内由微裂纹汇聚而形成的大的分隔裂纹的存在则可以有效地抑制烧结,降低涂层的热导率.
Yttria stabilized zirconia coatings were deposited using two different sets of parameters (N1,N2 coating).The microstructure features,such as total porosity and large porosity,were quantified by means of scanning electron microscope and image analysis.The three-dimensional distribution of microcracks and segmentation cracks was successfully revealed by the X-ray microscopy in the scanning electron microscope with three-dimensional microtomography capability.So the relationship between microstructure and thermal conductivity was found.At room temperature,thermal conductivity of N2 was lower than that of N1 due to larger pores and microcracks.At 1000℃ thermal conductivity of N1 was lower for the sintering of microcracks.The segmentation cracks formed by the propagation of microcracks could effectively reduce the thermal conductivity at high temperature.
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