On the use of B-alloyed MoSi 2 particles as crack healing agents in yttria stabilized zirconia thermal barrier coatings

Derelioglu, Z.; Carabat, A.L.; Song, Guanyu; Zwaag, Sybrand van der; Sloof, Willem G.

doi:10.1016/j.jeurceramsoc.2015.08.035

Cited by 70 publications

(43 citation statements)

References 25 publications

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“…Thus, one strategy employs eutectic mixtures whose melting point is lower than the oxidation temperature of SiC [14,15]. Another sealing mechanism resides in encapsulating the sealing agent (core-shell) by metal compounds, to produce a selective oxidation of the metal elements which prevents the sealing agent from further oxidation [10,16]. Other strategies focus on the development of reducing atmospheres surrounding the sealing particle during the thermal spray process [17].…”

Section: Introductionmentioning

confidence: 99%

Aqueous suspension processing of multicomponent submicronic Y-TZP/Al 2 O 3 /SiC particles for suspension plasma spraying

Carnicer

Alcázar

Sánchez

et al. 2018

Journal of the European Ceramic Society

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In order to obtain thermal barrier coatings by Suspension Plasma Spraying (SPS) process with potential new self-healing ability multicomponent submicronic Y-TZP/Al2O3/SiC suspensions were prepared. For this purpose, concentrated aqueous suspensions of individual components as well as the multicomponent mixture were studied and characterised in terms of colloidal stability and rheological behaviour to determine the best conditions for processing and preparation of the coatings. In the study, different dispersant contents and sonication times were tested. Subsequently, low concentrated suspensions were prepared to obtain preliminary thermal barrier coatings with the optimised feedstock. Thus, ceramic coatings were deposited by SPS and then characterised in order to assess the microstructure and phase distribution, in particular, the degree of preservation of the sealing agent, SiC, in the final coating as a previous indicator of its self-healing ability.

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Section: Introductionmentioning

confidence: 99%

Aqueous suspension processing of multicomponent submicronic Y-TZP/Al 2 O 3 /SiC particles for suspension plasma spraying

Carnicer

Alcázar

Sánchez

et al. 2018

Journal of the European Ceramic Society

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“…For TBC systems manufactured by APS failure is known to occur within the porous YSZ top coat close to the TGO layer [3]. Therefore, it has been proposed to embed 'healing' particles inside the YSZ top coat, which when intersected by a crack initiate a chemical reaction resulting in filling the microcracks with a well-adhering load bearing substance [5][6][7]. The healing action makes that the crack effectively disappears, restores the TBC mechanical integrity and extends the life time of the component [5].…”

Section: Introductionmentioning

confidence: 99%

“…It has been demonstrated that B-containing molybdenum disilicide (MoSi 2 ) could act as a suitable healing agent for YSZ-based TBCs. Upon oxidation initially silica (SiO 2 ) is formed as a reaction product, which fills the crack and subsequently turns into mechanically stable zircon (ZrSiO 4 ) due to a secondary solid state chemical reaction with the YSZ matrix [7,8]. To prevent premature oxidation of the MoSi 2 in the absence of a crack, the MoSi 2 particles need to be protected by a very thin yet dense layer of alumina [8], such that the self-heling mechanism would only be initiated by a crack intersecting the particle and opening the shell, allowing MoSi 2 oxidation.…”

Section: Introductionmentioning

confidence: 99%

Influence of embedded MoSi2 particles on the high temperature thermal conductivity of SPS produced yttria-stabilised zirconia model thermal barrier coatings

Kulczyk-Malecka

Zhang

Carr

et al. 2016

Surface and Coatings Technology

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Influence of embedded MoSi 2 particles on the high temperature thermal conductivity of SPS produced yttria-stabilised zirconia model thermal barrier coatings, Surface & Coatings Technology (2016), doi:10.1016/j.surfcoat.2016 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. A C C E P T E D Abstract:To prolong the lifetime of thermal barrier coatings (TBCs) recently a new method of microcrack healing has been developed, which relies on damage initiated thermal decomposition of embedded molybdenum disilicide (MoSi 2 ) particles within the TBC matrix.While these MoSi 2 particles have a beneficial effect on the structural stability of the TBC, the high thermal conductivity of MoSi 2 may have an unfavourable but as yet unquantified impact on the thermal conductivity of the TBCs.In this work the thermal conductivity of spark plasma sintering (SPS) produced yttria-

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“…At high-temperatures in an oxidizing gas environment, the MoSi 2 particles in the crack path forms a glassy silica (SiO 2 ) flowing into the crack-gap and reconnecting the fracture surfaces. Subsequently, the silica formed reacts with the matrix, resulting in the formation of crystalline zircon (ZrSiO 4 ) phase which, unlike the viscous silica, has a mechanical load bearing ability at high temperatures [2]. As the final healing product, ZrSiO 4 , is key in reestablishing the mechanical integrity of YPSZ, the mechanism and kinetics that governs its formation is highly relevant for the effective kinetics of strength restoration of damaged YPSZ and is therefore studied here.…”

Section: Introductionmentioning

confidence: 99%

“…Recent studies have indicated that the presence of boron in the MoSi 2 particles can increase the fluidity of the amorphous SiO 2 formed [2,17,18], a feature which is likely to enhance the subsequent reaction kinetics of SiO 2 with the ZrO 2 being the main constituent of YPSZ. Therefore, the work presented here focuses on the zircon formation from YPSZ and boron-free and boron containing MoSi 2 at high temperatures in an oxidizing gas environment.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of zircon formation in yttria partially stabilized zirconia as a result of oxidation of embedded molybdenum disilicide

et al. 2019

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This is an author's version published in: http://oatao.univ-toulouse.fr/24028 a b s t r a c t Recently MoSi 2 sacrificial particles embedded in yttria partially stabilized zirconia (YPSZ) have been proposed as attractive healing agents to realize significant extension of the lifetime of the thermally loaded structures. Upon local fracture of the YPSZ, the embedded healing particles in the path and in the vicinity of the crack react with the oxygen atoms transported via the crack and first fill the crack with a viscous glassy silica phase (SiO 2 ). The subsequent reaction between this freshly formed SiO 2 and the existing tetragonal ZrO 2 of the YPSZ leads to the formation of rigid crystalline zircon (ZrSiO 4 ), which is key in the crack-healing mechanism of YPSZ based materials. The isothermal kinetics of the self-healing reaction and the mechanism of zircon formation from the decomposing MoSi 2 and the surrounding YPSZ were assessed via X-ray diffraction (XRD). The obtained results revealed that at 1100 C the reaction between amorphous SiO 2 and YPSZ is completed after about 10 h. For a more accurate determination of the kinetics of the self-healing reaction, bilayer samples of YPSZ e MoSi 2 (with and without boron addition) were annealed in air over a temperature range of 1100e1300 C. This led to the formation of a MoSi 2 /amorphous (boro)silica/zircon/YPSZ multi-layer, which was investigated with scanning electron microscopy (SEM) and electron probe X-ray microanalysis (EPMA). Kinetic modeling of the growth of zircon and silica or borosilicate layers showed that zircon growth was dominated by the diffusion of Si 4þ in zircon whereas the growth of the silica or borosilicate layer was controlled by oxygen diffusion. Moreover, a significant increase in the rate of ZrSiO 4 formation was observed due to the presence of B in the MoSi 2 particles.

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On the use of B-alloyed MoSi 2 particles as crack healing agents in yttria stabilized zirconia thermal barrier coatings

Cited by 70 publications

References 25 publications

Aqueous suspension processing of multicomponent submicronic Y-TZP/Al 2 O 3 /SiC particles for suspension plasma spraying

Aqueous suspension processing of multicomponent submicronic Y-TZP/Al 2 O 3 /SiC particles for suspension plasma spraying

Influence of embedded MoSi2 particles on the high temperature thermal conductivity of SPS produced yttria-stabilised zirconia model thermal barrier coatings

Kinetics of zircon formation in yttria partially stabilized zirconia as a result of oxidation of embedded molybdenum disilicide

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