航空发动机燃烧室壁面“热斑”对热障涂层失效的影响

Effect of"Hot Spots"on the Wall of Aeroengine Combustion Chamber on the Failure of Thermal Barrier Coating

航空发动机燃烧室壁面热障涂层的脱落直接影响着相关部件使用寿命,其重要原因是“热斑”环境下涂层的局部烧结使得涂层内具有更复杂的应力状态,从而产生新的失效模式。采用ANSYS稳态流场与ABAQUS瞬态耦合对瓦片涂层系统进行分析,并借助断裂力学与实验方法对涂层的开裂规律进行表征,结果表明涂层具有升温350℃的“热斑”表面温度场与139 MPa的内部集中剪应力,并受此影响在“热斑”边缘区域优先发生以I型载荷为主导的面内复合型开裂失效。

The falling off of thermal barrier coating on the wall of aeroengine combustion chamber directly affects the service life of relevant components.The important reason is that the local sintering of the coating in the"hot spot"environment makes the coating have more complex stress state,resulting in new failure modes.The tile coating system is analyzed by ANSYS steady-state flow field and ABAQUS transient coupling,and the cracking law of the coating is characterized by fracture mechanics and experimental methods.The results show that the coating has a"hot spot"surface temperature field with a temperature rise of 350℃and an internal concentrated shear stress of 139 MPa.Under this influence,in-plane composite cracking failure dominated by type II load occurs preferentially in the edge area of"hot spot".