Thermal Shock Behavior of Nano-Structured Functionally Graded Thermal Barrier Coatings Deposited by Supersonic Plasma Spray

2007 ◽  
Vol 336-338 ◽  
pp. 2624-2627 ◽  
Author(s):  
Zhi Hai Han ◽  
Hai Jun Wang ◽  
Shi Kui Zhou ◽  
Bin Shi Xu
Keyword(s):  
Thermal Shock ◽  
Thermal Barrier Coatings ◽  
Functionally Graded ◽  
Thermal Barrier ◽  
Thermal Shock Test ◽  
Nano Structure ◽  
Barrier Coatings ◽  
Supersonic Plasma ◽  
Lower Temperature ◽  
Thermal Shock Behavior

The nano-structured functionally graded 8YSZ/NiCoCrAlY thermal barrier coatings (FG-TBCs) were prepared using a recently developed Supersonic Plasma Spraying (S-PS) system with dual powder feed ports. The alloy powders were fed into the lower temperature regions of the plasma plume through one of them to prevent it over molten and oxidation. The ceramic powders were fed into high temperature regions through another for fully melted. The thermal shock behavior of the FG-TBCs were investigated. It was found the totally 1mm thick FG-TBCs layer still maintained nano-structure form by TEM, and also exhibited a finely lamellate microstructure mixed by alloy and ceramic with gradient along the thickness direction by SEM. The FG-TBCs exhibit excellent thermal shock resistance due to it was still perfect without any spallation after thermal shock test over 200 cycles under heating by oxygenacetylene flam to 1250°C in 30s and then quenching into ambient water.

Investigation of Thermal Shock Behavior of Plasma-Sprayed NiCoCrAlY/YSZ Thermal Barrier Coatings

2012 ◽  
Vol 472-475 ◽  
pp. 246-250 ◽  
Author(s):  
Hossein Jamali ◽  
Reza Mozafarinia ◽  
Reza Shoja Razavi ◽  
Raheleh Ahmadi Pidani
Keyword(s):  
Thermal Shock ◽  
Thermal Barrier Coatings ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Thermal Shock Test ◽  
Barrier Coatings ◽  
Microstructural Evaluation ◽  
Mismatch Stress ◽  
Thermal Shock Behavior ◽  
Plasma Sprayed

ZrO2-8wt.%Y2O3 (8YSZ) thermal barrier coatings (TBCs) were deposited by atmospheric plasma spraying (APS) on NiCoCrAlY-coated Inconel 738LC substrates. The thermal shock behavior was investigated by quenching the samples in water with temperature of 20-25°C from 950°C. To study of failure mechanism results from thermal cycling, microstructural evaluation using scanning electron microscope (SEM), elemental analysis using energy dispersive spectroscopy (EDS) and phasic analysis using x-ray diffractometry (XRD) were done. The results revealed that failure of the TBC system was due to the spallation of ceramic top coat. Thermal mismatch stress was the major factor of TBC failure in thermal shock test.

Time-Dependent Behavior and Fracture of Functionally Graded Thermal Barrier Coatings under Thermal Shock

2005 ◽  
Vol 492-493 ◽  
pp. 379-384 ◽  
Author(s):  
Klod Kokini ◽  
Sudarshan V. Rangaraj
Keyword(s):  
Thermal Shock ◽  
Thermal Barrier Coatings ◽  
Functionally Graded ◽  
Yttria Stabilized Zirconia ◽  
Time Dependent ◽  
Thermal Barrier ◽  
Stabilized Zirconia ◽  
Barrier Coatings ◽  
Dependent Behavior ◽  
Bond Coat Alloy

The thermal fracture and its dependence on time-dependent behavior in functionally graded yttria stabilized zirconia - NiCoCrAlY bond coat alloy thermal barrier coatings was studied. The response of three coating architectures of similar thermal resistance to laser thermal shock tests was considered, experimentally and computationally.

Thermal shock behavior of EB-PVD thermal barrier coatings

2007 ◽  
Vol 201 (16-17) ◽  
pp. 7387-7391 ◽  
Author(s):  
Meiheng Li ◽  
Xiaofeng Sun ◽  
Wangyu Hu ◽  
Hengrong Guan
Keyword(s):  
Thermal Shock ◽  
Thermal Barrier Coatings ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Thermal Shock Behavior

Multiple Surface Cracking and Its Effect on Interface Cracks in Functionally Graded Thermal Barrier Coatings Under Thermal Shock

2003 ◽  
Vol 70 (2) ◽  
pp. 234-245 ◽  
Author(s):  
S. Rangaraj ◽  
K. Kokini
Keyword(s):  
Thermal Shock ◽  
Thermal Barrier Coatings ◽  
Architectural Design ◽  
Effective Properties ◽  
Mean Field ◽  
Functionally Graded ◽  
Analytical Models ◽  
Thermal Barrier ◽  
Thermal Fracture ◽  
Barrier Coatings

The thermal fracture behavior in functionally graded yttria stabilized zirconia–NiCoCrAlY bond coat alloy thermal barrier coatings was studied using analytical models. The response of three coating architectures of similar thermal resistance to laser thermal shock tests was considered. Mean field micromechanics models were used to predict the effective thermoelastic and time-dependent (viscoplastic) properties of the individual layers of the graded thermal barrier coatings (TBCs). These effective properties were then utilized in fracture mechanics analyses to study the role of coating architecture on the initiation of surface cracks. The effect of the surface crack morphology and coating architecture on the propensity for propagation of horizontal delamination cracks was then assessed. The results of the analyses are correlated with previously reported experimental results. Potential implications of the findings on architectural design of these material systems for enhanced thermal fracture resistance are discussed.

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