Evaluation Method of the Residual Stresses in Thermal Barrier Coating System Based on the Curvature of the Three-Layered Specimen
Evaluation Method of the Residual Stresses in Thermal Barrier Coating System Based on the Curvature of the Three-Layered Specimen
复制标题
基于三层试件曲率的热障涂层体系残余应力评价方法
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Y. Hasebe
中科院分区：
文献类型：
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作者：
Tomoyuki Hayase;H. Waki;Y. Hasebe
一种热障涂层(TBC)系统，由TBC面层(TC)、粘结层(BC)和基材组成。作用在涂层上的残余应力是材料力学的一个重要参数，因此需要对其进行评估。我们提出了一种用曲率法计算TBC系统各层上残余应力的简单方法。首先，根据涂层和基材之间的失配应变建立了一个三层模型。该方法使用喷丸处理的基材的曲率，喷丸和BC的BC系统样品，以及喷砂、BC和TC的TBC系统样品的曲率，而不是热喷涂过程中曲率的变化。然后，利用该方法对不同厚度的热障涂层系统试件的残余应力进行了计算。结果表明，所提出的方法在BC和TC中提供了合理的残余应力。最后，对涂层沉积后的热应力进行了理论计算，并利用实验测得的残余应力与理论热应力的差值估算了涂层在沉积过程中的淬火应力。利用淬火应力和热应力研究了热障涂层系统在热喷涂过程中残余应力的产生机理。
A thermal barrier coating (TBC) system consists of a TBC topcoat (TC), a bond coat (BC), and a substrate. Residual stress acting on a coating is a important parameter for materials mechanics and hence need to be evaluated. We propose a simple method for evaluating the residual stresses acting on each layer of a TBC system by using a curvature method. First, a three-layered model was constructed based on the misfit strain between the coatings and the substrate. This method uses the curvatures of the substrate with a blast treatment, the BC system specimen with the blast and BC, and the TBC system specimen with the blast, BC, and TC instead of a change in curvature during thermal spraying. Next, the residual stresses acting on the TBC system specimen with varying thicknesses were evaluated by using the proposed method. It was confirmed that the proposed method provides reasonable residual stresses in the BC and TC. Finally, the thermal stress after the coating deposition was theoretically evaluated, and the quenching stress of the coating during the deposition was evaluated by using the difference between the experimentally determined residual stress and the theoretical thermal stress. The mechanism for generating the residual stress in the TBC system during thermal spraying was investigated using the quenching stress and thermal stress.