Failure Behavior of Plasma-Sprayed Yttria-Stabilized Zirconia Thermal Barrier Coatings Under Three-Point Bending Test via Acoustic Emission Technique
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- 作者：L. Wang ; J. X. Ni ; F. Shao ; J. S. Yang ; X. H. Zhong…
- 关键词：acoustic emission (AE) ; failure ; plasma spraying ; thermal barrier coatings ; three ; point bending (3PB)
- 刊名：Journal of Thermal Spray Technology
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：26
- 期：1-2
- 页码：116-131
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Surfaces and Interfaces, Thin Films; Tribology, Corrosion and Coatings; Characterization and Evaluation of Materials; Operating Procedures, Materials Treatment; Analytical Chemistry;
- 出版者：Springer US
- ISSN：1544-1016
- 卷排序：26
文摘
In this paper, the failure behavior of plasma-sprayed yttria-stabilized zirconia thermal barrier coatings fabricated by atmospheric plasma spraying (APS-TBCs) under three-point bending (3PB) test has been characterized via acoustic emission (AE) technique. Linear positioning method has been adopted to monitor dynamic failure process of the APS-TBCs under 3PB test. The investigation results indicate that the variation of AE parameters (AE event counts, amplitudes and AE energy) corresponds well with the change of stress–strain curve of the loading processes. The failure mechanism was analyzed based on the characteristics of AE parameters. The distribution of frequency of crack propagation has been obtained. The AE signals came from two aspects: i.e., plastic deformation of substrates, initiation and propagation of the cracks in the coatings. The AE analysis combined with cross-sectional observation has indicated that many critical cracks initiate at the surface of the top-coat. And some main cracks tend to propagate toward the substrate/bond-coat interface. The actual failure mechanism of the APS-TBCs under 3PB test is attributed to the debonding of metallic coating from the substrates and the propagation of the horizontal crack along the substrate/bond-coat interface under the action of flexural moment.