摘要：利用大氣等離子噴涂制備了ZrO2涂層, 采用掃描電子顯微鏡結合圖像分析的方法對涂層的顯微結構特征(總氣孔率和大氣率)進行了量化表征。同時利用掃描電子顯微鏡附帶X射線掃描成像對涂層內部的微裂紋和大的分隔裂紋的三維分布進行了表征。據此建立了ZrO2涂層顯微結構與熱導率之間的關系。室溫下, 涂層N2的熱導率較N1的低, 因為涂層N2內氣孔和微裂紋數較多；在1000℃, 由于微裂紋的燒結作用導致熱導率增大, 所以涂層N2的熱導率較N1反而高。高溫下, 涂層內由微裂紋匯聚而形成的大的分隔裂紋的存在則可以有效地抑制燒結, 降低涂層的熱導率。

       Abstract：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 electronmicroscope 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.

       Key Word：ZrO2 coatings,microstructure,thermal conductivity,X-ray microscopy