A Simulation Study on the Crack Propagation Behavior of Nanostructured Thermal Barrier Coatings with Tailored Microstructure
2. Experimental Procedure
2.1. Materials and Plasma Spraying Process
2.2. Finite Element Model
2.2.1. Calculation Domain
2.2.2. Material Properties
2.2.3. Thermal Loads and Cracking Behavior
3. Results and Discussion
3.1. Analysis of Stress Field Distribution
3.2. Effects of Unmelted Nano-Particles and Their Content on the Cracking Propagation Behavior
- Accumulation of thermal stress: The tensile stress is mainly distributed in the horizontal or vertical direction of the UNPs. The compressive stress distributes inside the UNPs and the shear stress presents symmetrical distribution around the UNPs.
- Propagation of horizontal cracks: Under the tensile and shear stress, the cracks mainly propagated along the horizontal direction. The predefined cracks with 45° from the x/y-axis were a type I and II mixed-mode cracks. These cracks propagated along the direction parallel to the x-axis since the tensile stress σ22 and the shear stress σ12 were the main driving forces for the cracks propagation.
- “Capture effect” of UNPs: Cracks tended to propagate towards the tensile stress region of the surrounding UNPs. When the crack entered into the low elastic modulus and loose porous UNPs, the crack propagation was prevented.
- Experimental observation for spallation of TC: With the thermal cycles increasing, the ability of UNPs to prevent crack propagation decreased and the crack eventually entered into the UNPs or propagated along the interface between the UNPs and crystalline regions, resulting in the spallation of TC (Figure 11d).
- During the thermal cycling, the UNPs can effectively reduce the thermal stress of TC. The tensile stress and shear stress regions outside the UNPs enhance the initiation of cracks, while the compressive stress inside the UNPs can effectively prevent the cracks propagation.
- Arbitrarily oriented cracks mainly propagated parallel to the x-axis at the final stage of thermal cycle, indicating that tensile stress was the main driving force for the spallation failure of TBCs. Correspondingly, I and I–II mixed types of cracks are the major cracking failure patterns.
- The UNPs that distributed in the nanostructured coating had an obvious “capture effect” on the cracks, which means that many cracks easily accumulated in the tensile stress zone of the adjacent UNPs and a complex microcrack network generated at the periphery of UNPs.
- At the final stage of thermal cycling, the cracks eventually entered into the UNPs or propagated along the interface between the UNPs and crystalline region. Both the tensile stress and shear stress of TC were lower than those of BC. The spallation failure usually occurred at the TC/TGO interface.
Conflicts of Interest
- Evans, A.G.; Clarke, D.R.; Levi, C.G. The influence of oxides on the performance of advanced gas turbines. J. Eur. Ceram. Soc. 2008, 28, 1405–1419. [Google Scholar] [CrossRef]
- Busso, E.P.; Lin, J.; Sakurai, S. A mechanistic study of oxidation-induced degradation in a plasma-sprayed thermal barrier coating system. Part I: Model formulation. Acta Mater. 2001, 49, 1515–1528. [Google Scholar] [CrossRef]
- Vourdas, N.; Marathoniti, E.; Pandis, P.K.; Argirusis, C.; Sourkouni, G.; Legros, C.; Mirza, S.; Stathopoulos, V.N. Evaluation of LaAlO3 as top coat material for thermal barrier coatings. Trans. Nonferr. Metal. Soc. 2018, 28, 1582–1592. [Google Scholar] [CrossRef]
- Georgiopoulos, I.; Vourdas, N.; Mirza, S.; Andreouli, C.; Stathopoulos, V. LaAlO3 as overlayer in conventional thermal barrier coatings. Proc. Struc. Integ. 2018, 10, 280–287. [Google Scholar]
- Haoran, L.; Chang-An, W.; Chenguang, Z. Thermo-physical properties of rare-earth hexaaluminates LnMgAl11O19 (Ln: La, Pr, Nd, Sm, Eu and Gd) magnetoplumbite for advanced thermal barrier coatings. J. Eur. Ceram. Soc. 2015, 35, 1297–1306. [Google Scholar] [CrossRef]
- Bespalko, Y.; Kuznetsova, T.; Kriger, T.; Chesalov, Y.; Lapina, O.; Ishchenko, A.; Larina, T.; Sadykov, V.; Stathopoulos, V. La2Zr2O7/LaAlO3 composite prepared by mixing precipitated precursors: Evolution of its structure under sintering. Mater. Chem. Phys. 2020, 251, 1297–1306. [Google Scholar] [CrossRef]
- Zhang, S.; Lei, M.; Wan, M.; Huang, C. Morphology, Hardness and Wear Properties of Plasma Cladding NiCrCu Coating on M2 High-Speed Steel. Coatings 2020, 10, 641. [Google Scholar] [CrossRef]
- Pandey, A.; Patel, A.K.; Ariharan, S.; Kumar, V.; Sharma, R.K.; Kanhed, S. Enhanced Tribological and Bacterial Resistance of Carbon Nanotube with Ceria- and Silver-Incorporated Hydroxyapatite Biocoating. Nanomaterials 2018, 8, 363. [Google Scholar] [CrossRef][Green Version]
- Sun, L.; Guo, H.; Peng, H. Influence of partial substitution of Sc2O3 with Gd2O3 on the phase stability and thermal conductivity of Sc2O3-doped ZrO2. Ceram. Int. 2013, 39, 3447–3451. [Google Scholar] [CrossRef]
- Bansal, P.; Padture, N.P.; Vasiliev, A. Improved interfacial mechanical properties of Al2O3-13wt% TiO2 plasma-sprayed coatings derived from nanocry stalline powders. Acta Mater. 2003, 51, 2959–2970. [Google Scholar] [CrossRef]
- Lima, R.S.; Marple, B.R. Thermal spray coatings engineered from nanostructured ceramic agglomerated powders for structural, thermal barrier and biomedical applications: A review. J. Therm. Spray Technol. 2007, 16, 40–63. [Google Scholar] [CrossRef][Green Version]
- Wang, Z.B.; Zhou, C.G.; Xu, H.B. Effect of thermal treatment on the grain growth of nanostructured YSZ thermal barrier coating prepared by air plasma spraying. Chin. J. Aeronaut. 2004, 17, 119–123. [Google Scholar] [CrossRef][Green Version]
- Wang, L.; Wang, Y.; Sun, X.G. Microstructure and surface residual stress of plasma sprayed nanostructured and conventional ZrO2-8 wt.% Y2O3 thermal barrier coatings. Surf. Interf. Anal. 2011, 43, 869–880. [Google Scholar] [CrossRef]
- Liang, B.; Ding, C.X. Thermal shock resistances of nanostructured and conventional zirconia coatings deposited by atmospheric plasma spraying. Surf. Coat. Technol. 2005, 197, 185–192. [Google Scholar] [CrossRef]
- Wang, L.; Li, D.C.; Yang, J.S.; Shao, F.; Zhong, X.H.; Zhao, H.Y. Modeling of thermal properties and failure of thermal barrier coatings with the use of finite element methods: A review. J. Eur. Ceram. Soc. 2016, 36, 1313–1331. [Google Scholar] [CrossRef]
- Kyaw, S.; Jones, A.; Jepson, M.A.E. Effects of three-dimensional coating interfaces on thermo-mechanical stresses within plasma spray thermal barrier coatings. Mater. Des. 2017, 125, 189–204. [Google Scholar] [CrossRef][Green Version]
- Wei, Z.Y.; Cai, H.N.; Li, C.J. Comprehensive dynamic failure mechanism of thermal barrier coatings based on a novel crack propagation and TGO growth coupling model. Ceram. Int. 2018, 44, 22556–22566. [Google Scholar] [CrossRef]
- Wei, Z.Y.; Cai, H.N. Comprehensive effects of TGO growth on the stress characteristic and delamination mechanism in lamellar structured thermal barrier coatings. Ceram. Int. 2019, 209, 5300–5304. [Google Scholar] [CrossRef]
- Zhang, L.; Bai, Y.; Yu, F.L. Performance of plasma-sprayed thermal barrier coating with engineered unmelted nano-particle contents. Surf. Coat. Technol. 2019, 368, 67–78. [Google Scholar] [CrossRef]
- Bai, Y.; Han, Z.H.; Li, H.Q.; Xu, C.; Xu, Y.L.; Ding, C.H. Structure-property differences between supersonic and conventional atmospheric plasma sprayed zirconia thermal barrier coatings. Surf. Coat. Technol. 2011, 205, 3833–3839. [Google Scholar] [CrossRef]
- Abaqus Analysis User’s Manual (Version 6.7). Available online: http://126.96.36.199:2080/v6.7/books/usb/default.htm (accessed on 22 July 2020).
- Kyaw, S.; Jones, A.; Hyde, T. Predicting failure within TBC system: Finite element simulation of stress within TBC system as affected by sintering of APS TBC, geometry of substrate and creep of TGO. Eng. Fail. Anal. 2013, 27, 150–164. [Google Scholar] [CrossRef]
- Ranjbar-Far, M.; Absi, J.; Mariaux, G.; Dubois, F. Simulation of the effect of material properties and interface roughness on the stress distribution in thermal barrier coatings using finite element method. Mater. Des. 2010, 31, 772–781. [Google Scholar] [CrossRef]
- Bäker, M. Finite element simulation of interface cracks in thermal barrier coatings. Comput. Mater. Sci. 2012, 64, 79–83. [Google Scholar] [CrossRef]
- Ranjbar-Far, M.; Absi, J.; Shahidi, S. Impact of the non-homogenous temperature distribution and the coatings process modeling on the thermal barrier coatings system. Mater. Des. 2011, 32, 728–735. [Google Scholar] [CrossRef]
- Clarke, D.R. The lateral growth strain accompanying the formation of a thermally grown oxide. Acta Mater. 2003, 51, 1393–1407. [Google Scholar] [CrossRef]
- Ranjbar-Far, M.; Absi, J.; Mariaux, G. Finite element modeling of the different failure mechanisms of a plasma sprayed thermal barrier coatings system. J. Therm. Spray Technol. 2012, 21, 1234–1244. [Google Scholar] [CrossRef]
- Ranjbar-far, M.; Absi, J.; Mariaux, G.; Smith, D.S. Crack propagation modeling on the interfaces of thermal barrier coating system with different thickness of the oxide layer and different interface morphologies. Mater. Des. 2011, 32, 4961–4969. [Google Scholar] [CrossRef]
- Białas, M. Finite element analysis of stress distribution in thermal barrier coatings. Surf. Coat. Technol. 2008, 202, 6002–6010. [Google Scholar] [CrossRef]
- Nabarro, F. Do we have an acceptable model of power-law creep? Mater. Sci. Eng. A 2004, 387, 659–664. [Google Scholar] [CrossRef][Green Version]
- Zhu, W.; Zhang, Z.B.; Yang, L. Spallation of thermal barrier coatings with real thermally grown oxide morphology under thermal stress. Mater. Des. 2018, 146, 180–193. [Google Scholar] [CrossRef]
- Zhu, W.; Yang, L.; Guo, J.W.; Zhou, Y.C.; Lu, C. Determination of interfacial adhesion energies of thermal barrier coatings by compression test combined with a cohesive zone finite element model. Int. J. Plast. 2015, 64, 76–87. [Google Scholar] [CrossRef]
- Aktaa, J.; Sfar, K.; Munz, D. Assessment of TBC systems failure mechanisms using a fracture mechanics approach. Acta Mater. 2005, 53, 4399–4413. [Google Scholar] [CrossRef]
- Wang, L.; Zhong, X.H.; Shao, F. What is the suitable segmentation crack density for atmospheric plasma sprayed thick thermal barrier coatings with the improved thermal shock resistance? Appl. Surf. Sci. 2018, 431, 101–111. [Google Scholar] [CrossRef]
- Jayaprakash, K.; Ponnusami, S.A.; Sergio, T. Modelling the fracture behavior of thermal barrier coatings containing healing particles. Mat. Des. 2018, 157, 75–86. [Google Scholar]
- Wang, L.; Yang, J.S.; Ni, J.X. Influence of cracks in APS-TBCs on stress around TGO during thermal cycling: A numerical simulation study. Surf. Coat. Technol. 2016, 285, 98–112. [Google Scholar] [CrossRef]
|TC||1.8 × 10−10||1||1000|
|TGOs||7.3 × 10−8||1||1000|
|BC||6.5 × 10−19||4.6||≤600|
|BC||2.2 × 10−12||3.0||700|
|BC||1.8 × 10−7||1.6||≥800|
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Zhang, L.; Wang, Y.; Fan, W.; Gao, Y.; Sun, Y.; Bai, Y. A Simulation Study on the Crack Propagation Behavior of Nanostructured Thermal Barrier Coatings with Tailored Microstructure. Coatings 2020, 10, 722. https://doi.org/10.3390/coatings10080722
Zhang L, Wang Y, Fan W, Gao Y, Sun Y, Bai Y. A Simulation Study on the Crack Propagation Behavior of Nanostructured Thermal Barrier Coatings with Tailored Microstructure. Coatings. 2020; 10(8):722. https://doi.org/10.3390/coatings10080722Chicago/Turabian Style
Zhang, Lei, Yu Wang, Wei Fan, Yuan Gao, Yiwen Sun, and Yu Bai. 2020. "A Simulation Study on the Crack Propagation Behavior of Nanostructured Thermal Barrier Coatings with Tailored Microstructure" Coatings 10, no. 8: 722. https://doi.org/10.3390/coatings10080722