Li Chun, Xiao Ping, Cernik Robert
School of Materials, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
J Appl Crystallogr. 2020 Feb 1;53(Pt 1):69-75. doi: 10.1107/S1600576719016327.
The residual strain distribution has been measured as a function of depth in both top coat and bond coat in as-received and heat-treated air plasma sprayed thermal barrier coating samples. High-energy synchrotron X-ray beams were used in transmission to produce full Debye-Scherrer rings whose non-circular aspect ratio gave the in-plane and out-of-plane strains far more efficiently than the sinψ method. The residual strain in the bond coat is found to be tensile and the strain in the β phase of the as-received sample was measured. The residual strains observed in the top coat were generally compressive (increasing towards the interface), with two kinds of nonlinear trend. These was a 'jump' feature near the interface, and in some cases there was another 'jump' feature near the surface. It is shown how these trend differences can be correlated to cracks in the coating.
在接收态和热处理后的大气等离子喷涂热障涂层样品中，已测量了面涂层和粘结涂层中残余应变随深度的分布。使用高能同步加速器X射线束进行透射，以产生完整的德拜-谢乐环，其非圆形纵横比能比sinψ法更有效地给出面内和面外应变。发现粘结涂层中的残余应变为拉伸应变，并测量了接收态样品β相中的应变。面涂层中观察到的残余应变通常为压缩应变（向界面处增加），呈现两种非线性趋势。在界面附近有一个“跳跃”特征，在某些情况下，表面附近还有另一个“跳跃”特征。展示了这些趋势差异如何与涂层中的裂纹相关联。
