热障涂层系统内粘结层循环塑性研究  

STUDY ON THE CYCLIC PLASTICITY OF BOND COAT IN THERMAL BARRIER COATING SYSTEMS

作　　者：苏罗川 张伟旭[1] 王铁军[1] 

机构地区：[1]机械结构强度与振动国家重点实验室,航天航空学院西安交通大学,西安710049

出　　处：《固体力学学报》2013年第S1期99-104,共6页Chinese Journal of Solid Mechanics

基　　金：国家973课题(2013CB0357017);国家自然科学基金(11021202;10902081)

摘　　要：在热障涂层系统内,热生长氧化层(TGO)在热循环作用下的位移失稳通过诱发涂层的开裂、剥落而导致系统失效.而粘结层(BC)内的塑性积累又是控制TGO失稳的一个最为关键因素.本文采用数值模型观察了BC在热循环作用下的塑性积累.TGO在高温下的生长以及蠕变行为在计算中同时被考虑.计算结果表明BC内的塑性积累主要发生在热循环的热震阶段,而高温保温阶段的TGO增厚主要导致BC在热震阶段发生塑性屈服以及反向屈服所需要的温度变化幅值降低.因此,在TGO每经过一次高温生长后,BC在随后的热震阶段将在更小的温度变化范围内屈服,而这将导致更大的塑性积累出现.The displacement instability of the thermally grown oxide(TGO)under thermal cycling is a key factor inducing the failure of thermal barrier coating systems by large scale buckling and spallation.The accumulation of plastic strains in bond coat(BC)is the most critical factor controlling the displacement instability of TGO.A numerical model was used to investigate the cyclic plasticity in BC under thermal cycling.The behavior of creep and thermal growth in TGO at high temperature was simulated.The plastic strain in BC mainly accumulates in the process of thermal shock.The thickening of TGO in the process of thermal growth decreases the amplitude of temperature change that is required to cause initial yielding and reversed yielding of BC.In the following thermal shock process,BC would yield and reversed yield at the lower temperature,which can cause larger plastic deformation in this thermal cycling.

关 键 词：热障涂层 循环塑性 粘结层 热循环 

分 类 号：TG174.4[金属学及工艺—金属表面处理]