目的 研究等离子喷涂热障涂层(APS-TBCs)内部脱粘裂纹尺寸对陶瓷层温度场与烧结行为的影响。方法 采用有限元模型研究不同尺寸脱粘裂纹对其上方陶瓷层温度场变化规律的影响，并通过梯度热循环试验对裂纹上方陶瓷层烧结行为进行研究，采用扫描电子显微镜(SEM)分析陶瓷层表面和断面的组织形貌，并使用图片法对裂纹上方陶瓷层不同区域的孔隙率进行分析。结果 裂纹上方陶瓷层温度变化区域的面积取决于裂纹尺寸，且最高温度始终位于裂纹中心的上方陶瓷层表面，随着裂纹宽度向两端依次递减，其对应的上方温度依次递减。在本试验条件下，随着脱粘裂纹尺寸的增加，涂层厚度方向的最高温度以线性形式增加，裂纹尺寸每增加0.5 mm，其上方陶瓷层同一位置处的温度增加约30 ℃，且最高温度区域随之增大。裂纹长度超过3 mm时，在脱粘裂纹热阻效应下，裂纹上方陶瓷层区域的温度升高。裂纹越长，上方陶瓷层整体温度提升越高，不仅导致陶瓷层发生相变和烧结的区域增大，还使得相变和烧结速率升高。不同梯度热循环次数下，陶瓷层表面和内部均出现了数量和长度不等的脱粘、垂直裂纹，烧结面积逐渐增大。脱粘裂纹长度为4 mm时，其最大宽度约40 μm。结论 脱粘裂纹上方陶瓷层温度变化以表面最高温度处为中心向四周呈放射性递减。越靠近陶瓷层表面，层状组织信息越少，相应区域的孔隙率越小，烧结和相变程度逐渐增加，使涂层发生脱落失效的可能性进一步增加。

The work aims to research the influence of temperature distribution and sintering behavior of yttria-stabilized zirconia (YSZ) coating over the delamination crack propagation in atmospheric plasma spraying thermal barrier coatings (APS- TBCs). The finite element model (FEM) was used to analyse the temperature distributions of YSZ coating above the delamination crack with different sizes, and the sintering behavior of YSZ coating was examined via gradient thermal cycling test. scanning electron microscopy (SEM) was employed to analyse the microstructure of the surface and the cross section of YSZ coating. The image method was used to analyse the porosity of YSZ coating. The results show that the high-temperature area of the YSZ coating depends on the crack size, and the highest temperature is always on the surface of the YSZ coating above the crack center. The temperature decreases from the crack center to its tip. In this case, the maximum temperature across the thickness of the coating increases linearly with increasing of the delamination crack size. The temperature at the same position above the YSZ coating increases by about 30 ℃ when the crack size increases 0.5 mm. The maximum temperature region increases. When the crack length exceeds 3 mm, the temperature in the YSZ coating region above the crack increases due to the thermal barrier effect of the delamination crack. The temperature of the whole YSZ coating above the crack increases with the length of the crack, which not only leads to the increase of the area where the YSZ coating undergoes phase transformation and sintering, but also increases the phase transformation and sintering rate. The number and length of delamination and vertical cracks on the surface and inside of YSZ coating are different under different thermal cycles, and the sintering area increases gradually. The maximum width of the delamination crack is about 40 μm, corresponding to the 4 mm crack. The temperature of YSZ coating above the delamination crack decreases radially from the center to the tip. The layered structure and the porosity of YSZ coating disappears gradually from the interface to the free surface of the YSZ coatings. Thus, the sintering and phase transformation degree of the corresponding area is gradually increased, furthermore, the possibility of coating failure is further increased.