Damage evolution of TBC system under in-phase thermo-mechanical tests

Kitazawa, Rumi; Tanaka, Makoto; Kagawa, Yutaka; Liu, Y.F.

doi:10.1016/j.mseb.2009.12.022

Cited by 27 publications

(11 citation statements)

References 20 publications

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“…The TGO growth behaviors of the TBC systems with two different ceramic top coatings generally result in similar TGO-thickness values. 5,14,[21][22][23][24][25][26][27] Another different characteristic of top coatings is their high oxygen permeability. When Zr 4+ and Mg 2+ are displaced, two oxygen vacancies occur in the stabilization of MgO+ZrO 2 .…”

Section: Discussionmentioning

confidence: 99%

Comparison of microstructures and oxidation behaviors of ytria and magnesia stabilized zirconia thermal barrier coatings (TBC)

Döleker¹,

Ozgurluk²,

Özkan³

et al. 2018

Mater. Tehnol.

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Thermal barrier coatings (TBCs) provide protection to minimize aggressive environmental conditions such as oxidation, corrosion and thermal shocks occurring at high temperatures. In this study, a CoNiCrAlY metallic-bond coat was deposited on an Inconel 718 superalloy substrate with a thickness about 100 μm using the atmospheric-plasma-spray (APS) method. The production of TBCs was accomplished by depositing Y2O3 partially stabilized zirconia (YSZ) and MgO-stabilized zirconia (MSZ) as two different ceramic top-coating materials, having the total thickness of 300 μm. The specimens were subjected to a metallographic investigation before the oxidation tests; their surface roughness, porosity, hardness and microstructural properties were investigated and then compared with the results obtained after the oxidation tests. The TBC systems were subjected to isothermal-oxidation tests at 900°C and 1000°C for (8, 24, 50 and 100) h. After the oxidation tests, XRD, SEM and EDX elemental analyses were carried out and the changes in the thickness and structure of the thermally grown oxide (TGO) layer were investigated. A remarkable change occurred between the top and the bond coat in the TBC systems depending on the increasing time and temperature. The TGO layer thickness showed an increase. At the interface, Al2O3 and other mixed-oxide layers occurred. Before and after the oxidation, XRD analyses showed that YSZ had a tetragonal phase and a bit of a monoclinic phase. The MSZ coating included tetragonal, monoclinic and cubic phases at the end of the oxidation. This phase transformation causes a large volume increase in an MSZ lattice. Due to this volume increase, MSZ coatings suffer more damage than YSZ coatings. Keywords: atmospheric plasma spray, thermal barrier coatings, oxidation, ZrO2-Y2O3, ZrO2-MgO Prevleke kot termi~ne prepreke (TBCs; angl.: Thermal Barrier Coatings) zagotavljajo za{~ito pred agresivnim okoljem in zmanj{ajo oksidacijo, korozijo in termi~ni {ok zaradi obratovanja pri visokih temperaturah. V {tudiji avtorji obravnavajo kovinsko difuzijsko vezano prevleko na osnovi CoNiCrAlY, nane{eno na podlago iz superzlitine Inconel 718 debeline okoli 100 μm, ki je izdelana z metodo atmosferskega plazemskega napr{evanja (APS; angl: Atmospheric Plasma Spray). Dve razli~ni kerami~ni TBCs, celotnih debelin 300 μm, so izdelali z nana{anjem z Y2O3 delno stabiliziranega cirkonijevega oksida ZrO2 (YSZ, angl.: Yttria partially Stabilized Zirconia) in z MgO-stabiliziranega cirkonijevega oksida (MSZ; Magnesia Stabilized Zirconia). Na izdelanih vzorcih so izvedli primerjalne metalografske preiskave, pred in po oksidacijskih testih, in sicer: hrapavost povr{ine, poroznost, trdoto in mikrostrukturne lastnosti. TBC-sistema sta bila izpostavljena testom izotermalne oksidacije pri 900°C in 1000°C za (8, 24, 50 in 100) ur. Po oksidacijskih testih so izvedli XRD, SEM, EDX-elementne analize, kakor tudi ugotovili spremembe debeline in strukture termi~no zrasle oksidne plasti (TGO; angl.: Thermally Grown Oxide). Avtorji so ugotovili znatne ...

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Section: Discussionmentioning

confidence: 99%

Comparison of microstructures and oxidation behaviors of ytria and magnesia stabilized zirconia thermal barrier coatings (TBC)

Döleker¹,

Ozgurluk²,

Özkan³

et al. 2018

Mater. Tehnol.

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“…The function of the ceramic top coat is to insulate the metallic substrate from high surface temperature, thereby lowering the component's temperature and reducing the oxidation and hot corrosion of bond coatings while simultaneously reducing cyclic thermal strains (Gurrappa and Sambasiva 2006). Recently, Kitazawa et al (2010) have reported that a temperature gradient of 150°C can be achieved by using a ceramic TBC (Y 2 O 3 -ZrO 2 top coat) on superalloy components. In most cases, the top coat and bond coats are applied by plasma spraying; however, sputtering and electron beam physical vapor deposition (EBPVD) are also used.…”

Section: Improving Gt Efficiency Through Thermal Barrier Coatings Tbcmentioning

confidence: 99%

“…Nye Thermodynamics Corporation (NTC) 2011; Zeren 1982;Schulz et al 2008;Braue et al 2007;Huda et al 2011;Jianting 2011;Cao and Loria 2005;Sajjadi and Nategh 2001;Sajjadi et al 2002;Zickler et al 2009;Perepezko 2009;Todd 1989;Kansai Electric Power Company (KEPCO) 2011;Diologent and Caron 2004;Kennedy 2005;Kitazawa et al 2010;Pint et al 1998;Wright and Gibbons 2007;Choi et al 2010;Walston 2004;Troczynski et al 1996;DeMasi-Marcinand and Gupta 1994;Movchan 1996;Schulz et al 1997;Padture et al 2002;Boccaccini and Zhitomirsky 2002;Boccaccini et al 2006;Besra and Liu 2007;Corni et al 2008;Dusoulier et al 2011;Doungdaw et al 2005;Mohanty et al 2008;Put et al 2003 Use TBC using EPD/EBPVD MHI, J-series engine operating at TIT = 1,600°C has achieved efficiency exceeding 60%…”

Section: A New Chart For Gt Researchers Designers and Manufacturersmentioning

confidence: 99%

Enhancing power output and profitability through energy-efficiency techniques and advanced materials in today’s industrial gas turbines

Huda

Zaharinie

Al-Ansary

2014

Int J Mech Mater Eng

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This paper reviews and integrates the latest energy-efficiency improvement techniques to recently developed superalloys and coatings for enhancing power output and profitability in today's industrial gas turbines (GTs). It has been shown that the retrofitting of inlet air cooling and steam injected gas technology technologies in simple turbines can boost power output from 30 to 48.25 MW and improve generation efficiency from 29.9% to 33.4%. It has been reviewed that for improving efficiency of power plants beyond 60%, it is important to use higher turbine inlet temperature (TIT) in combined cycle gas turbine by applying single-crystal nickel-based superalloys and thermal barrier coating involving closed-loop steam cooling. It has been shown that an increase of the TIT by 56°C can result in increased revenue of US$8/kW to the manufacturer of the original rating, provided the GT is sold for US$200/kW. In view of the latest development in GT technology, which enables them to be operated at TIT = 1,600°C, it is recommended to develop superalloys based on higher-melting temperatures (Mo-based superalloys). A new chart for increasing power output has been developed so as to enable the GT designers to manufacture GT engines with enhanced profitability.

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“…TBCs enhance the fuel efficiency by enabling higher temperature operations and extending lifetime performance of hot-section components in aircraft and gas turbine engines. For aircraft engines, many researches [1][2][3][4] have focused on the thermomechanical fatigue loadings which adversely influence the durability of TBCs, and their failure mechanisms. The ceramic top coat in a typical TBC system is made of 6-8 wt% yttria-stabilized zirconia (YSZ), which has low thermal conductivity, superior thermal stability and similar coefficient of thermal expansion (CTE) to metallic substrate.…”

Section: Introductionmentioning

confidence: 99%

Effect of thermal cycling frequency on the durability of Yb-Gd-Y-based thermal barrier coatings

Lyu

Choi

et al. 2019

Surface and Coatings Technology

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2019). Effect of thermal cycling frequency on the durability of Yb-Gd-Y-based thermal barrier coatings. Surface and Coatings Technology. AbstractThe effects of thermal cycling frequency and buffer layer on the crack generation and thermal fatigue behaviors of Yb-Gd-Y-stabilized zirconia (YGYZ)-based thermal barrier coatings (TBCs) were investigated through thermally graded mechanical fatigue (TGMF) test. TGMF tests with low-(period of 10 min) and high-frequency (period of 2 min) cycling were performed at 1100 o C with a 60 MPa tensile load. Different cycling frequencies in TGMF test generate two kinds of crack propagation modes. The sample with low-frequency cycling condition shows penetration cracks in the YGYZ top coat, and multiple narrow vertical cracks are generated in high-frequency cycling. To enhance the thermomechanical properties, different buffer layers were introduced into the TBC systems, which were deposited with the regular (RP) or high-purity 8 wt% yttria stabilized zirconia (HP-YSZ) feedstock. The purity of the feedstock powder used for preparing the buffer layer affected the fracture behavior, showing a better thermal durability for the TBCs with the HP-YSZ in both frequency test conditions. A finite element model is developed, which takes creep effect into account due to thermal cycling. The model shows the high stresses at the interfaces between different layers due to differential thermal expansion. The failure mechanisms of YGYZ-based TBCs in TGMF test are also proposed. The vertical cracks are preferentially created, and then the vertical and horizontal cracks will be propagated when the vertical cracks are impeded by pores and micro-cracks.

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Damage evolution of TBC system under in-phase thermo-mechanical tests

Cited by 27 publications

References 20 publications

Comparison of microstructures and oxidation behaviors of ytria and magnesia stabilized zirconia thermal barrier coatings (TBC)

Comparison of microstructures and oxidation behaviors of ytria and magnesia stabilized zirconia thermal barrier coatings (TBC)

Enhancing power output and profitability through energy-efficiency techniques and advanced materials in today’s industrial gas turbines

Effect of thermal cycling frequency on the durability of Yb-Gd-Y-based thermal barrier coatings

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