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针对带等离子喷涂热障陶瓷涂层的圆筒金属基体结构在典型热循环载荷作用条件下的力学响应进行了数值计算,基于陶瓷层中的应力结果对陶瓷层剥落失效机理展开了分析.计算时对陶瓷层材料分别按理想线弹性本构和黏塑性本构模型开展了模拟.分析发现,陶瓷层的界面(横向)开裂存在两种模式:在降温过程中,陶瓷层容易出现界面波峰处的Ⅰ型开裂与腰部位置处的Ⅱ型开裂;在升温过程中,陶瓷层容易发生垂直开裂使结构中出现陶瓷层/基体的界面端,界面端部严重的应力集中效应使陶瓷层容易在该处横向开裂形成界面处的边裂纹.
The mechanical response of the cylindrical metal substrate with plasma sprayed thermal barrier ceramic coating under typical thermal cycling load is numerically calculated and the failure mechanism of the ceramic layer is analyzed based on the stress results in the ceramic layer. According to the ideal linear elastic constitutive model and viscoplastic constitutive model, the ceramic layer materials are simulated respectively. It is found that there are two modes for the interface (lateral) cracking of the ceramic layer: during the cooling process, the ceramic layer tends to appear at the interface peak Type I cracking and type II cracking at the waist; during the heating process, the ceramic layer is prone to vertical cracking, so that the ceramic layer / matrix interface appears in the structure. The severe stress concentration effect at the end of the interface makes the ceramic layer easy to be there Lateral cracking forms edge cracks at the interface.