High-Temperature Performance of Self-Healing SiC-YSZ Thermal Barrier Coatings Deposited by Using Various Plasma Spray Concepts

2021 ◽  
Author(s):  
Mohammad Hassanzadeh ◽  
Paweł Sokołowski ◽  
Radek Musalek ◽  
Jan Medricky ◽  
Stefan Csaki
Keyword(s):  
High Temperature ◽  
Thermal Barrier Coatings ◽  
Plasma Spray ◽  
Gas Turbines ◽  
Isothermal Oxidation ◽  
Atmospheric Plasma ◽  
Flash Method ◽  
Thermal Barrier ◽  
Self Healing ◽  
Barrier Coatings

Abstract In this study; a novel self-healing concept is considered in order to increase the lifetime of thermal barrier coatings (TBCs) in modern gas turbines. For that purpose; SiC healing particles were introduced to conventional 8YSZ topcoats by using various plasma spray concepts; i.e.; composite or multilayered coatings. All topcoats were sprayed by SG-100 plasma torch on previously deposited NiCrAlY bondcoats produced by conventional atmospheric plasma spraying. Coatings were subjected to thermal conductivity measurements by laser flash method up to 1000°C; isothermal oxidation testing up to 200h at 1100°C and finally thermal cyclic fatigue (TCF) lifetime testing at 1100°C. Microstructural coating evaluation was performed by scanning electronic microscope (SEM); in the as-produced and post high-temperature tested states. This was done to analyze the self-healing phenomena and its influence on the hightemperature performance of the newly developed TBCs.

Fundamental Coating Development Study to Improve the Isothermal Oxidation Resistance and Thermal Cycle Durability of Thermal Barrier Coatings

2006 ◽  
Vol 522-523 ◽  
pp. 247-254 ◽  
Author(s):  
Taiji Torigoe ◽  
Hidetaka Oguma ◽  
Ikuo Okada ◽  
Guo Chun Xu ◽  
Kazuhisa Fujita ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Atmospheric Plasma ◽  
Zirconia Ceramic ◽  
Thermal Barrier ◽  
Temperature Oxidation ◽  
Barrier Coatings ◽  
Oxidation Properties

Thermal barrier coatings(TBCs) are used in high temperature gas turbines to reduce the surface temperature of cooled metal parts such as turbine blades[1]. TBC consist of a bondcoat (e.g. MCrAlY where M is Co, Ni, CoNi, etc.) and a partially stabilized zirconia ceramic topcoat. Usually, the MCrAlY bondcoat is applied by LPPS (low pressure plasma spray) or HVOF(high velocity oxi-fuel spray). The topcoat is applied by APS (atmospheric plasma splay) or EB-PVD (electron beam-physical vapor deposition). High temperature oxidation properties, thermal barrier properties and durability of TBC are very important to increase the reliability in high temperature service. In this study, new TBC has been investigated. The new TBC consists of a two-layered bondcoat (LPPS-MCrAlY plus dense PVD overlay MCrAlY) and the EB-PVD type YSZ columnar structure topcoat. As a result of evaluation tests, it was confirmed that the new TBC had better oxidation properties and durability than a conventional TBC system.

Bond coating issues in thermal barrier coatings for industrial gas turbines

2005 ◽  
Vol 219 (2) ◽  
pp. 101-107 ◽  
Author(s):  
I. G. Wright ◽  
B. A. Pint
Keyword(s):  
High Temperature ◽  
Oxide Layer ◽  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
Metallic Surface ◽  
Thermal Barrier ◽  
Protective Oxide ◽  
Barrier Coatings ◽  
Bond Coating ◽  
Industrial Gas Turbines

Thermal barrier coatings are intended to work in conjunction with internal cooling schemes to reduce the metal temperature of critical hot gas path components in gas turbine engines. The thermal resistance is typically provided by a 100-250 μm thick layer of ceramic (most usually zirconia stabilized with an addition of 7–8 wt% of yttria), and this is deposited on to an approximately 50 μ thick, metallic bond coating that is intended to anchor the ceramic to the metallic surface, to provide some degree of mechanical compliance, and to act as a reservoir of protective scale-forming elements (Al) to protect the underlying superalloy from high-temperature corrosion. A feature of importance to the durability of thermal barrier coatings is the early establishment of a continuous, protective oxide layer (preferably α-alumina) at the bond coating—ceramic interface. Because zirconia is permeable to oxygen, this oxide layer continues to grow during service. Some superalloys are inherently resistant to high-temperature oxidation, so a separate bond coating may not be needed in those cases. Thermal barrier coatings have been in service in aeroengines for a number of years, and the use of this technology for increasing the durability and/or efficiency of industrial gas turbines is currently of significant interest. The data presented were taken from an investigation of routes to optimize bond coating performance, and the focus of the paper is on the influences of reactive elements and Pt on the oxidation behaviour of NiAl-based alloys determined in studies using cast versions of bond coating compositions.

Interfacial Kinetics of High Temperature Oxidation in YSZ Thermal Barrier Coatings With Bond Coatings of NiCoCrAlY With 0.25% Hf

2009 ◽  
Author(s):  
Winston Soboyejo ◽  
Patrick Mensah ◽  
Ravinder Diwan
Keyword(s):  
High Temperature ◽  
Thermal Barrier Coatings ◽  
High Temperature Oxidation ◽  
Structural Evolution ◽  
Isothermal Oxidation ◽  
Thermally Grown Oxide ◽  
Thermal Barrier ◽  
Temperature Oxidation ◽  
Barrier Coatings ◽  
Thermally Grown

This paper presents the results of an experimental study of the high-temperature isothermal oxidation behavior and micro-structural evolution in plasma sprayed thermal barrier coatings (TBCs) at temperatures between 900 and 1200 °C. Two types of specimens were produced for testing. These include a standard and vertically cracked (VC) APS. High temperature oxidation has been carried out at 900, 1000, 1100 and 1200 °C. The experiments have been performed in air under isothermal conditions. At each temperature, the specimens are exposed for 25, 50, 75 and 100 hours. The corresponding microstructures and microchemistries of the TBC layers are then examined using scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy EDS. Changes in the dimensions of the thermally grown oxide (TGO) layer are determined as functions of time and temperature. The evolution of bond coat microstructures/interdiffusion zones and thermally grown oxide (TGO) layers are compared in TBCs with standard (STD) and vertically cracked (VC) microstructures.

The Effect of Laser Glazing on High Temperature Oxidation Resistance of Thermal Barrier Coatings

2012 ◽  
Vol 433-440 ◽  
pp. 315-318
Author(s):  
Seyid Fehmi Diltemiz ◽  
Melih Cemal Kushan
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
High Temperature Oxidation ◽  
304 Stainless Steel ◽  
Thermal Barrier ◽  
Laser Glazing ◽  
Temperature Oxidation ◽  
Barrier Coatings

Thermal barrier coatings (TBCs) have been widely used by aero and land based gas turbines to protect hot section parts from oxidation and thermal loads. These coatings are generally consisting of multiple layers of coating (usually two) with each layer having a specific function. TBCs are generally deposited with air plasma spray (APS) or electron beam physical vapor deposition (EB-PVD) techniques. In this paper plasma sprayed TBCs were deposited on to 304 stainless steel substrates then ceramic surfaces were glazing with Nd-YAG laser. Metallographic examinations were applied to the samples to investigate microstructural changes in glazed ceramic layer. Both glazed and as-coated samples were subjected to oxidation tests to measure the high temperature oxidation resistance. The tests showed that, laser glazing is beneficial to oxidation resistance of TBCs. This improvement is attributed to sintering of zirconia layer which act as oxygen barrier and formed during glazing process.

Investigation on Improved-Durability Thermal Barrier Coatings

2018 ◽  
pp. 60-78
Author(s):  
Mohammad Hassanzadeh ◽  
Mohsen Saremi ◽  
Zia Valefi ◽  
Amir Hossein Pakseresht
Keyword(s):  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
Temperature Stability ◽  
Thermal Barrier ◽  
Self Healing ◽  
Barrier Coatings ◽  
Structural Modifications ◽  
Coating Delamination ◽  
New Generation ◽  
Development Methods

Concurrent with the development of new generation of gas turbines, many attempts have been made to introduce advanced thermal barrier coatings with lower thermal conductivity and higher temperature stability. Most of the research to improve TBCs performance are based on two general approaches: structural modifications and chemical modifications. In most cases, the improvements in some properties are at the expense of loss of some other properties. Changing in the TBCs architecture and the application of multilayer coatings, consisting of layers with engineered properties based on the requirements, is a solution to achieve a combination of desired properties. In all of these development methods it is to be understood that the principle is reducing the possibility of formation of cracks, but, once formed, all such cracks can grow under and thermal cycles and eventually lead to coating delamination and spallation. Self-healing is the most precious phenomenon to overcome this problem.

Preparation and Distribution Analysis of Thermal Barrier Coatings Deposited on Multiple Vanes by Plasma Spray-Physical Vapor Deposition Technology

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
J. Mao ◽  
M. Liu ◽  
C. G. Deng ◽  
C. M. Deng ◽  
K. S. Zhou ◽  
...  
Keyword(s):  
Thermal Barrier Coatings ◽  
Plasma Spray ◽  
Vapor Deposition ◽  
Gas Turbines ◽  
Physical Vapor Deposition ◽  
Ceramic Layer ◽  
Thermal Barrier ◽  
Distribution Analysis ◽  
Barrier Coatings ◽  
Bond Layer

The multicomponent NiCoCrAlTaY coating as bond layer as well as the zirconia stabilized by yttrium oxide (YSZ) coating as top ceramic layer was deposited on duplex vane surface by plasma spray-physical vapor deposition (PS-PVD) system. The thickness and microstructure of thermal barrier coatings (TBCs) under the influence of duplex vane geometry were presented in this article. It has been proven that the entire surface of duplex vane was covered by NiCoCrAlTaY and YSZ coatings. The position with thickest coating was found close to the leading edge and trailing edge of the vane. In those places, the coating was approximately 80–100% thicker than in the other areas on duplex vane. The obtained results indicate that it is possible to manufacture the TBCs including metallic bond layer and top ceramic layer by PS-PVD process on multiple vanes for gas turbines.

Thermal Cyclic Behaviour of Conventional YSZ and Mullite-YSZ Thermal Barrier Coatings

2020 ◽  
Vol 405 ◽  
pp. 417-422
Author(s):  
David Jech ◽  
Pavel Komarov ◽  
Michaela Remešová ◽  
Lucie Dyčková ◽  
Karel Slámečka ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Barrier Coatings ◽  
Phase Stability ◽  
Bond Coat ◽  
Cyclic Oxidation ◽  
Thermally Grown Oxide ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Mullite Phase

Nowadays commonly used thermal barrier coatings (TBC) are based on yttria stabilized zirconia (YSZ). Addition of mullite phase into the YSZ coating can improve resulting high temperature properties. The contribution focuses on high temperature cyclic oxidation behaviour of two TBC systems with different top coats (TC) deposited by the means of atmospheric plasma spraying. The initial mullite-YSZ powder mixture consisted of 29 vol. % of mullite and 71 vol. % of YSZ. The conventional TBC system consisted of ~ 150 µm thick NiCoCrAlYHfSi bond coat (BC) and ~ 300 µm thick YSZ top coat. The experimental mullite-YSZ (MYSZ) TBC system consisted of ~ 150 µm thick NiCoCrAlYHfSi bond coat, ~ 100 µm thick YSZ interlayer and ~ 200 µm thick mullite-YSZ top coat. The experimental TBC proved higher lifetime, durability and phase stability and also lower grow rate of thermally grown oxide (TGO) compared to conventional TBC. Lifetime, phase stability and changes in the microstructure of TBCs after the furnace cyclic oxidation test were evaluated by the means of scanning electron microscopy equipped with EDX analyzer and X-ray diffraction techniques. Oxidation kinetics of TGO was calculated based on thickness determined utilizing digital image analysis.

Structure and Performance of YSZ Thermal Barrier Coatings Irradiated by High Intensity Pulsed Ion Beam

2012 ◽  
Vol 538-541 ◽  
pp. 2377-2381 ◽  
Author(s):  
Xian Xiu Mei ◽  
Yue Liu ◽  
Xue Ma ◽  
You Nian Wang
Keyword(s):  
Thermal Barrier Coatings ◽  
High Intensity ◽  
Ion Beam ◽  
Xrd Analysis ◽  
Isothermal Oxidation ◽  
Atmospheric Plasma ◽  
Cubic Phase ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Micro Cracks

The thermal barrier coatings (TBC) of the yttria-stabilized zirconia (YSZ) has been deposited by the atmospheric plasma spraying (APS),followed by the irradiation of high intensity pulsed ion beam (HIPIB) with the voltage of 250 KV and the ion current density of 300 A/cm2 and pulsed times of 2, 5, 10 and 20, respectively. The X-ray diffraction (XRD) analysis reveals that the coating is characterized by the tetragonal ZrO2 phase instead of the cubic phase and the original monoclinic phase after the irradiation. The scanning electron micros cope analysis demonstrates that the HIPIB treatment leads to a smooth TBC surface, but produces micro-cracks and round grain at the surface. This implies that the plasma erupts during the ion beam interaction with the coatings with poor thermal conductivity, and the micro-cracks were produced in the cooling process. The isothermal oxidation experiment performed at 1050°C in air and suggests that the oxidation resistance of the coating can be largely enhanced after HIPIB treatment.

Life Prediction of High-Temperature MCrAlY Coatings Based on Microstructural Observations

2014 ◽  
Vol 922 ◽  
pp. 143-148 ◽  
Author(s):  
Robert Eriksson ◽  
Kang Yuan ◽  
Sten Johansson ◽  
Ru Lin Peng ◽  
Xin Hai Li
Keyword(s):  
High Temperature ◽  
Thermal Barrier Coatings ◽  
Bond Coat ◽  
Gas Turbines ◽  
Life Prediction ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Mcraly Coatings ◽  
Barrier Coating ◽  
Coating Composition

Thermal barrier coatings are commonly used in gas turbines for protection against high tem-perature and oxidation. Life prediction of oxidation protective coatingsmay be done bymicrostructure-based techniques such as -depletion based life criteria. In this study, a thermal barrier coating sys-tem, with an overlay NiCoCrAlY coating as bond coat, was oxidised up to 10000 h at 900 C. Themicrostructure was studied and related to Al depletion. It was found that a -depletion based lifecriterion could not be used for the studied coating composition and temperature as it would be tooconservative. A 0-depletion based model was instead suggested and supported by interdiffusion sim-ulation.

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