On the performance and failure mechanism of thermal barrier coating systems used in gas turbine blade applications: Influence of bond coat/superalloy combination

Tawancy, H. M.; Mohammad, A.I.; Al‐Hadhrami, Luai M.; Dafalla, Hatim; Alyousf, F.K.

doi:10.1016/j.engfailanal.2015.07.023

Cited by 34 publications

(11 citation statements)

References 45 publications

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“…The objective of the top ceramic coating is to reduce the metal temperature. A metallic bond coat is used to enhance the bonding between the top coat and the underlying super-alloy and to protect the super-alloy from oxidation and hot corrosion [8]. Yttria-stabilized Zirconia [YSZ] containing 6-8%Y2O3 is known as a state of the art thermal barrier coating topcoat [9].…”

Section: Introductionmentioning

confidence: 99%

“…Defects lead to a lower value for thermal conductivity and a lower thermal conductivity implies a longer service life, as heat transfer to the substrate is reduced. Lower heat transfer into the substrate also leads to lower damage to the coating interface, where most of the failure occurs [8]. To achieve lower values for thermal conductivity, better strain tolerance and higher lifetime, the distribution of cracks and pores in the coating needs to be optimized [14].…”

Section: Introductionmentioning

confidence: 99%

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Modelling Thermal Conductivity Of Porous Thermal Barrier Coatings For High-Temperature Aero Engines Using Five Phase Model

Ghai¹,

Chen²,

Baddour³

2018

Progress in Canadian Mechanical Engineering

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Thermal Barrier Coatings (TBC) are used to shield hot sections of gas turbine engines, helping to prevent the melting of metallic surfaces. This paper proposes a Five-phase model to calculate the effective thermal conductivity of a TBC, taking into consideration the effect of various defects. By comparing the predicted values with experimental results, it was shown that the proposed five-phase model can predict the thermal conductivity of ceramic coatings closer to the actual values.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Modelling Thermal Conductivity Of Porous Thermal Barrier Coatings For High-Temperature Aero Engines Using Five Phase Model

Ghai¹,

Chen²,

Baddour³

2018

Progress in Canadian Mechanical Engineering

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“…These mixed oxides grow rapidly and thus lead to high local volumetric expansion and causes high local stresses within the coating layers upon heating and cooling. It is reported that the residual stresses associated with TGO growth is one of the main reasons for the top coat cracking followed by system spallation and failure.…”

Section: Resultsmentioning

confidence: 99%

Protective pre‐deposited slurry dip‐coating alumina layer on TBC system

Abdeldaim

Mahallawy

2017

Materials & Corrosion

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In the present study, a thin intermediate protective α‐alumina layer was pre‐deposited by slurry dip‐coating technique on APS–CoNiCrAlY bond coat prior depositing APS–YSZ as top coat. The alumina layer acts as barrier for oxygen diffusion to protect the metallic bond coat from excessive oxidation. The new TBC was compared with the standard TBC system which comprises of Ni‐superalloy substrate, CoNiCrAlY bond coat and YSZ top coat concerning the behavior under thermal cycling at 1150 °C. The samples were investigated before and after thermal cycling by optical microscopy, scanning electron microscopy (SEM) equipped with energy dispersive X‐ray spectroscopy (EDS), and X‐ray diffraction analysis (XRD). Image analysis was used to compare between the microstructure by measuring the crack lengths and the thermally grown oxide layer (TGO) average thickness after thermal cycling. It was observed that a more uniform and compact α‐Al2O3 TGO was formed in the new TBC system after thermal cycling comparing to the commercial one. It was, also, found that the alumina intermediate layer has the potential to reduce the length of the cracks and the average thickness of TGO by suppressing the detrimental mixed oxides, like Cr2O3, CoO, NiO, and (Ni, Co)(Cr, Al)2O4, thus, improving the TBC durability.

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“…A TBC is a multi-layer coating consisting of the top coat (ceramic) and the inner layer (the bond coat) between the ceramic and the substrate. [20][21] Recently, R. Kitazawa et al 22 have reported that a temperature gradient of 150°C can be achieved using a ceramic TBC (Y 2 O 3 -ZrO 2 top coat) on superalloy components.…”

Section: Tbc Developmentsmentioning

confidence: 99%

Energy-efficient gas-turbine blade-material technology – a review

Huda¹

2017

Mater. Tehnol.

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Energy-efficient gas turbines (GTs) with reduced emissions have significantly contributed to sustainable development. However, these advanced engines, operating at turbine inlet temperatures (TITs) as high as 1.600°C, require the development of highly creep-resistant materials for application in hotter-section components of GTs. This paper first reviews recent advancements in the development of creep-resistant superalloys and their microstructural control, including stable gamma-prime raft structures. Then a comparative analysis of recently developed SC superalloys is presented to enable GT designers to select appropriate materials for hotter energy-efficient GT engines. It is recommended to develop new creep-limited alloys based on the metals with higher melting temperatures (e.g., Mo and Nb alloyed with silicon); these future alloys are proposed as prospective candidates for hotter energy-efficient GTs. Keywords: energy-efficient gas turbines, gas-turbine blades, turbine inlet temperature, single-crystal superalloys Energetsko u~inkovite plinske turbine (angl. GT) z zmanj{animi emisijami so mo~no prispevale pri trajnostnem razvoju. Vendar pa ti napredni stroji, ki delujejo pri temperaturah do 1600°C v vstopnem delu turbine zahtevajo, za uporabo komponent v vro~em delu, razvoj materialov odpornih na lezenje.^lanek predstavlja prvi pregled trenutnega napredka pri razvoju na lezenje odpornih superzlitin in kontrolo njihovih mikrostruktur, vklju~no s stabilno zgradbo gama-prime. Predstavljena je analiza pred kratkim razvitih SC superzlitin, tako da je konstrukterjem GT omogo~ena izbira primernega materiala za bolj vro~e, energijsko u~inkovite GT stroje. Predlagan je razvoj novih zlitin z omejenim lezenjem, ki temeljijo na kovinah z vi{jo temperature tali{~a (npr. Mo in Nb legiran s silicijem); te bodo~e zlitine so predlagane kot perspektivne za bolj vro~e, energijsko u~inkovite GT. Klju~ne besede: energijsko u~inkovite plinske turbine, lopatice plinskih turbin, vhodna temperatura turbine, monokristalne superzlitine

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On the performance and failure mechanism of thermal barrier coating systems used in gas turbine blade applications: Influence of bond coat/superalloy combination

Cited by 34 publications

References 45 publications

Modelling Thermal Conductivity Of Porous Thermal Barrier Coatings For High-Temperature Aero Engines Using Five Phase Model

Modelling Thermal Conductivity Of Porous Thermal Barrier Coatings For High-Temperature Aero Engines Using Five Phase Model

Protective pre‐deposited slurry dip‐coating alumina layer on TBC system

Energy-efficient gas-turbine blade-material technology – a review

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