热障涂层的三维界面形貌与热应力关系

Relations between 3 dimension interface topography with thermal stress of thermal barrier coatings

使用等离子喷涂方法制备出双层热障涂层(粘结层为Ni-Cr-Al-Y,陶瓷层为ZrO2).使用ABAQUS有限元分析软件,采用间接耦合分析的方法,模拟计算了喷涂过程中陶瓷层/粘结层间三维结构椭圆界面的应力场分布,得出了粘结层表面三维椭球形貌单元位置和尺寸与热应力分布之间的关系.模拟结果表明,涂层制备后,椭球形貌单元位置和尺寸对于陶瓷层和粘结层的界面应力影响较为明显,在形貌单元尺寸一定的情况下,涂层边界附近形貌单元的热应力相对较大,是涂层失效的危险单元,单元角点处为各个单元的危险点,当短半轴为20μm时界面危险点应力σyy达到最大值324 MPa.

Double layer thermal barrier coatings（bond coating is Ni-Cr-Al-Y and ceramic coating is ZrO2） was prepared by atmospheric plasma sprayed method.Using ABAQUS software,the thermal stress distribution of 3 dimension ellipse interface topography between bond coating and ceramic coating was numerically simulated by indirect coupling method.Relations between thermal stress with location and size of ellipse topography unit were obtained.The calculating results show that the stress is affected by location and size obviously and stress of boundary topography unit is bigger than that of center unit when the size of unit is invariable.The boundary topography units are danger unit and corner points are danger points.The stress of danger point reaches 324 MPa when short half axes is 20.