Phase-angle effects on damage mechanisms of thermal barrier coatings under thermomechanical fatigue

Baufeld, Bernd; Tzimas, Evangelos; Hähner, P.; Müllejans, Harald; Peteves, S. D.; Moretto, Ph.

doi:10.1016/s1359-6462(01)01106-x

Cited by 22 publications

(6 citation statements)

References 10 publications

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“…It is important to identify the parameters which affect the crack growth mechanism and thus the a e-mail : t.beck@fz-juelich.de lifetime of thermal barrier coatings [3,4]. However, studies on TMF behaviour of TBC systems reported in the literature are limited and differences in experimental procedure make the comparison of published results very difficult.…”

Section: Introductionmentioning

confidence: 99%

TBCs for Gas Turbines under Thermomechanical Loadings: Failure Behaviour and Life Prediction

Beck

Trunova

Herzog³

et al. 2012

EPJ Web of Conferences

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Abstract. The present contribution gives an overview about recent research on a thermal barrier coating (TBC) system consisted of (i) an intermetallic MCrAlY-alloy Bondcoat (BC) applied by vacuum plasma spraying (VPS) and (ii) an Yttria Stabilised Zirconia (YSZ) top coat air plasma sprayed (APS) at Forschungszentrum Juelich, Institute of Energy and Climate Research (IEK-1). The influence of high temperature dwell time, maximum and minimum temperature on crack growth kinetics during thermal cycling of such plasma sprayed TBCs is investigated using infrared pulse thermography (IT), acoustic emission (AE) analysis and scanning electron microscopy. Thermocyclic life in terms of accumulated time at maximum temperature decreases with increasing high temperature dwell time and increases with increasing minimum temperature. AE analysis proves that crack growth mainly occurs during cooling at temperatures below the ductile-to-brittle transition temperature of the BC. Superimposed mechanical load cycles accelerate delamination crack growth and, in case of sufficiently high mechanical loadings, result in premature fatigue failure of the substrate. A life prediction model based on TGO growth kinetics and a fracture mechanics approach has been developed which accounts for the influence of maximum and minimum temperature as well as of high temperature dwell time with good accuracy in an extremely wide parameter range.

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Section: Introductionmentioning

confidence: 99%

TBCs for Gas Turbines under Thermomechanical Loadings: Failure Behaviour and Life Prediction

Beck

Trunova

Herzog³

et al. 2012

EPJ Web of Conferences

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“…This point makes the above approaches less easy to defend and quite difficult to validate. Moreover, cracks in the TGO layer could be healed at high temperature: specific thermo-mechanical fatigue (TMF) loading condition could lead, without macroscopic breakdown, to a greater oxide thickness than critical thickness evaluated for isothermal loading [19,20]. However in service, components are subjected to both high and low temperature stages, with frequency variations, and in which maxima reached for thermal and mechanical loading could be non-synchronous.…”

Section: Introductionmentioning

confidence: 99%

Interfacial damage based life model for EB-PVD thermal barrier coating

Courcier

Maurel

Rémy

et al. 2011

Surface and Coatings Technology

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“…A irfoils in aeroturbines experience a wide range of thermomechanical fatigue (TMF) loadings that can adversely influence the durability of the system 1–3 . The loadings can be in phase or out of phase in both tension and compression.…”

Section: Introductionmentioning

confidence: 99%

“…To be representative of an actual airfoil, the system to be investigated incorporates a bond coat and a thermal barrier coating (TBC). Prior in‐phase TMF experiments have been conducted on hollow cylindrical (axisymmetric) and plate type (uniaxial) TBC specimens 1–4 …”

Section: Introductionmentioning

confidence: 99%

Thermomechanical Fatigue Damage Evolution in a Superalloy/Thermal Barrier System Containing a Circular Through Hole

et al. 2011

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The results of an investigation of thermomechanical fatigue (TMF) on a superalloy specimen, with an applied thermal barrier coating (TBC) and a circular through hole, are presented. Tensile loads were applied in phase with increasing temperature. Damage evolution in the form of cracks develops in the TBC adjacent to the hole. These cracks run perpendicular to the loading axis. Stress mapping of the thermally grown oxide (TGO) using luminescence spectroscopy determined an increase in compressive residual stress with increasing TMF cycling. Scanning electron microscopy examination, following cross sectioning, determined the TBC cracks to be vertical separations of the columnar yttria-stabilized zirconia (YSZ) top coat. Microscopic damage mechanisms in the form of plasticity (bending of YSZ columns) and TGO cracking were observed. Imperfections in the bond coat are associated with these vertical separations. Energydispersive element mapping of these imperfections indicated a composition of alumina and mixed Cr, Co, and Ni oxides.C. Levi-contributing editor

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Phase-angle effects on damage mechanisms of thermal barrier coatings under thermomechanical fatigue

Cited by 22 publications

References 10 publications

TBCs for Gas Turbines under Thermomechanical Loadings: Failure Behaviour and Life Prediction

TBCs for Gas Turbines under Thermomechanical Loadings: Failure Behaviour and Life Prediction

Interfacial damage based life model for EB-PVD thermal barrier coating

Thermomechanical Fatigue Damage Evolution in a Superalloy/Thermal Barrier System Containing a Circular Through Hole

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