Fracture behavior of TBCs with cooling hole structure under cyclic thermal loadings
Source abstract
Abstract
Abstract The integrity of thermal barrier coatings (TBCs) plays an important role in the performance of turbine blades, nevertheless the effect of cooling hole on fracture of TBCs have been less studied. The present work aimed to study the stress evolution and fracture behavior of TBCs with cooling hole under cyclic thermal loadings. Cyclic thermal tests were conducted and the cracking behavior of TBCs around cooling hole was examined using scanning electron microscope (SEM). TBCs exhibited two types of cracks near the hole edge, i.e. surface crack in the top coat and interfacial crack, which could lead to local TBC spallation and shorten the TBC lifetime. To disclose the fracture mechanism, finite element (FE) analysis was also performed. The computed residual stress values were consistent with those measured by Raman spectroscopy tests. FE simulations indicated that the free-edge effect facilitated interfacial peeling and shear stresses near the cooling hole, and hence promoted the initiation of interfacial crack in TBCs. With the increase of thermal loading cycles, the interfacial crack propagated and then coalesced with the surface cracks in the top coat, leading to the final spallation of TBCs at the cooling hole.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: High-Temperature Coating Behaviors · Nuclear Materials and Properties · Particle Dynamics in Fluid Flows
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (27)
Show source-provided references
1. Thermal-barrier coatings for more efficient gas-turbine engines10.1557/mrs.2012.232 ↗
2. Interfacial peeling moments and shear forces at free edges of multilayers subjected to thermal stresses10.1111/j.1551-2916.2006.00924.x ↗
3. Influence of material properties on temperature and thermal stress of thermal barrier coating near a normal cooling hole10.1016/j.ijheatmasstransfer.2011.08.026 ↗
4. Mechanisms controlling the durability of thermal barrier coatings10.1016/S0079-6425(00)00020-7 ↗
5. Finite element simulation of stresses in a plasma-sprayed thermal barrier coating with a crack at the TGO/bond-coat interface10.1016/j.surfcoat.2018.01.024 ↗
6. A parametric study of the stress state of thermal barrier coatings Part I: creep relaxation
7. Spallation of thermal barrier coatings with real thermally grown oxide morphology under thermal stress10.1016/j.matdes.2018.03.019 ↗
8. Comprehensive dynamic failure mechanism of thermal barrier coatings based on a novel crack propagation and TGO growth coupling model10.1016/j.ceramint.2018.09.028 ↗
9. Numerical analyses of the residual stress and top coat cracking behavior in thermal barrier coatings under cyclic thermal loading10.1016/j.engfracmech.2018.04.031 ↗
10. Modeling and simulation of the temperature and stress fields in a 3D turbine blade coated with thermal barrier coatings10.1016/j.surfcoat.2017.03.012 ↗
11. Numerical stress analysis of the TBC-film cooling system under operating conditions considering the effects of thermal gradient and TGO growth10.1016/j.surfcoat.2018.10.020 ↗
12. Deformation and cracking near a hole in an oxide-forming alloy foil subjected to thermal cycling10.1016/j.actamat.2012.09.077 ↗
13. Thermomechanical fatigue damage evolution in a superalloy/thermal barrier system containing a circular through hole10.1111/j.1551-2916.2011.04539.x ↗
14. The stress distribution around holes in thermal barrier coatings10.1016/j.msea.2004.03.062 ↗
15. Edge effect on crack patterns in thermally sprayed ceramic splats10.1007/s11666-016-0505-6 ↗
16. Stress distributions in plasma-sprayed thermal barrier coatings under thermal cycling in a temperature gradient10.1115/1.4002209 ↗
17. Piezo-spectroscopic coefficients of tetragonal-prime yttria-stabilized zirconia10.1111/j.1551-2916.2007.01622.x ↗
18. Damage mechanisms and lifetime behavior of plasma-sprayed thermal barrier coating systems for gas turbines—Part II: Modeling10.1016/j.surfcoat.2008.06.132 ↗
19. The effect of samples geometry and thermal cycling test type on the thermal shock behaviour of plasma sprayed TBCs10.1002/ppap.200931706 ↗
20. Prediction of critical rupture of plasma-sprayed yttria stabilized zirconia thermal barrier coatings under burner rig test via finite element simulation and in-situ acoustic emission technique10.1016/j.surfcoat.2019.03.063 ↗
21. Thermal stresses in elastic multilayer systems10.1016/S0040-6090(02)00699-5 ↗
22. The free-edge stress singularity at an interface between bilinear materials10.1016/0020-7683(91)90050-P ↗
23. Thermomechanical peeling in multilayer beams and plates—a solution from first principles10.1016/j.ijsolstr.2004.07.013 ↗
24. Stress analysis of the thermal barrier coating system near a cooling hole considering the free-edge effect
25. Simulation of the effect of material properties and interface roughness on the stress distribution in thermal barrier coatings using finite element method10.1016/j.matdes.2009.08.005 ↗
26. Effect of TGO creep on top-coat cracking induced by cyclic displacement instability in a thermal barrier coating system10.1016/j.surfcoat.2014.06.052 ↗
27. Numerical study on the competitive cracking behavior in TC and interface for thermal barrier coatings under thermal cycle fatigue loading10.1016/j.surfcoat.2018.11.006 ↗