Thermographic analysis and modelling of the delamination crack growth in a thermal barrier coating on Fecralloy substrate
Thermographic analysis and modelling of the delamination crack growth in a thermal barrier coating on Fecralloy substrate
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DOI：
10.1016/j.surfcoat.2012.12.002
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发表时间：
2013-02
影响因子：
5.4
通讯作者：
M. Schweda;T. Beck;M. Offermann;L. Singheiser
中科院分区：
文献类型：
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作者：
M. Schweda;T. Beck;M. Offermann;L. Singheiser
采用热像技术分析了等离子喷涂ZrO 2热障涂层系统在热循环过程中的分层裂纹扩展。使用简化的模型系统，其中具有相对低的屈服应力和蠕变强度的Fe-Cr-Al-Y合金（Fecralloy Eisen-Chrom™）基底模拟粘合涂层。分层裂纹面积作为循环次数的函数进行测量，并通过红外脉冲热成像观察和量化的增长机制。在此基础上，建立了描述分层裂纹扩展的经验模型。与大多数常用的模型相比，本模型计算分层裂纹面积（而不是长度），考虑多个裂纹的形成（而不是一个），在不同的时间裂纹萌生（而不是同时萌生），裂纹在样品上的位置和彼此以及裂纹萌生点的统计空间分布。模型方法能很好地满足脱层裂纹扩展的关键特征。虽然只使用了一组参数，该模型捕捉时间的不连续性的裂纹面积增加，因此分散的分层面积在给定的时间。
The delamination crack growth in a plasma sprayed ZrO2thermal barrier coating system during thermal cycling was analysed by thermography. A simplified model system was used where a Fe–Cr–Al–Y alloy (Fecralloy Eisen-Chrom™) substrate with relative low yield stress and creep strength simulates the bond coat. The delamination crack area was measured as a function of cycle number and the growth mechanisms were observed and quantified by infrared pulse thermography. Based on this, an empirical model was created to describe the delamination crack growth. In contrast to most of the usual models, the present model calculates delamination crack area (instead of length), accounts for formation of multiple cracks (instead of one), for crack initiation at different times (instead simultaneous initiation), for the positions of the cracks on the sample and to each other as well as for the statistic spatial distribution of the crack initiation sites. The key features of delamination crack growth are met properly by the model approach. Although only one set of parameters was used, the model captures temporal discontinuities of the crack area increase and therefore scatter of delaminated area at a given time.