Mechanical and electrical characterisation of a phase transformation in thermal barrier coatings

Shinmi, Akio; Zhao, Xiaofeng; Xiao, Ping

doi:10.1016/j.surfcoat.2010.10.038

Cited by 20 publications

(6 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…14 Based on the results of the Part-I, 14 the durations of stage I at 1000°C and 1300°C were approximately 50 hours and 10 hours, respectively. However, the significant formation of monoclinic phase often needs a much longer incubation period (e.g., 100-150 hours at 1300°C [30][31][32] ). Therefore, it is reasonable to conclude that the sintering at stage I is relatively unaffected by the phase change.…”

mentioning

confidence: 99%

A comprehensive sintering mechanism for TBCs‐Part II: Multiscale multipoint interconnection‐enhanced initial kinetics

et al. 2017

View full text Add to dashboard Cite

During thermal exposure, the sintering process of the plasma‐sprayed thermal barrier coatings (PS‐TBCs) presents significant two‐stage kinetics, as reported in the Part I. As a companion study, this part aims to reveal the mechanism responsible for the ultrafast sintering kinetics when initially exposed, since the initial short stage (stage‐I) often finishes most increment of the mechanical and thermal properties. A detailed examination of the pore healing behavior was carried out, based on the experimental result in Part I that the dominant structural change at the stage‐I is the significant healing at intersplat pore tips. Results show that the smooth splat surface, which made up the wedge‐shaped intersplat pores, changed to a rough surface with multiscale convexs after high‐temperature thermal exposure. Moreover, the multiscale roughening is highly sensitive to various orientations of the columnar grains inside the splats. Subsequently, multipoint connection between the counter‐surfaces of the intersplat pores was formed by the bridging of multiscale convexs. This multiscale multipoint connection between pore surfaces significantly accelerated the healing of intersplat pores, which can be dominantly responsible for the ultrafast sintering kinetics at the stage‐I. This comprehensive sintering mechanism could offer some positive suggestions toward prolonging the thermal‐insulating effect of TBCs.

show abstract

mentioning

confidence: 99%

A comprehensive sintering mechanism for TBCs‐Part II: Multiscale multipoint interconnection‐enhanced initial kinetics

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The sequential growth with correspondence C provided direct proof of the phenomenological theory. In addition, correspondence A was also observed frequently in partially-transformed grains, while it was rotated along the shear direction [1][2][3][4][5][6][7][8][9][10] t to an atypical A form. This hindered the self-accommodation process due to the large lattice mismatch.…”

Section: Discussionmentioning

confidence: 99%

“…8 Over the last several decades, the experimental characterization of monoclinic variant features has been one of the main challenges in the analysis of YSZ. The transformation generally occurs on the nanoscale and the size of the monoclinic variants is of the order of tens of nanometers, while Raman spectroscopy, 9 X-ray diffraction, 10 and neutron scattering 11 can only measure macroscopic features. Transmission electron microscopy (TEM) can observe the variants with nanoscale resolution.…”

Section: Introductionmentioning

confidence: 99%

Growth modes for monoclinic yttria‐stabilized zirconia during the martensitic transformation

Wang

Gauvin

et al. 2017

J Am Ceram Soc

View full text Add to dashboard Cite

The tetragonal to monoclinic martensitic transformation of plasma-sprayed 3 mol % Y 2 O 3 -ZrO 2 coatings is investigated by electron backscatter diffraction. The original metastable tetragonal phase shows an approximate "basal" texture with {001} t parallel to the coating surface. Based on the orientation analysis, plenty of monoclinic variants with atypical correspondence which indicates the c t axis transforms to the a m axis where (100) m //(001) t , (010) m , and (001) m //{110} t are clearly identified in addition to the correspondence where the c t axis transforms to the c m axis. Moreover, three growth modes are proposed and discussed according to strain accommodation. The observed sequential growth obeys the correspondence of the c t axis to the c m axis. Fourfold growth combines the correspondences of the c t axis to the c m and a m axes. The interleaving growth follows the correspondences of the c t axis to the c m axis within three tetragonal domains. These phenomena demonstrate the typical twin-related and self-accommodating configuration, which is in agreement with the phenomenological theory. These finding provide fundamental insight into the martensitic transformation mechanism and demonstrate a route for increasing the lifetime by controlling the tetragonal to monoclinic phase transformation. K E Y W O R D S electron backscatter diffraction, martensitic transformation, orientation relationship, yttria-stabilized zirconia

show abstract

“…At present, the sintering of APS coatings mainly focuses on the evolution of thermodynamic parameters of coatings with sintering time [6][7][8][9][10]. Based on experimental observations of microstructure evolution of APS coatings during sintering [11][12][13], Siebert et al found that the formation of an interlaminar sintered neck would increase the Young's modulus of the coating, and no phase change would occur in this process [14][15][16]. The experiments of Hardwicke et al showed that the formation of a sintered neck strengthened the heat transfer between plates and thus increased the thermal conductivity of the coating [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

LC/8YSZ TBCs Thermal Cycling Life and Failure Mechanism under Extreme Temperature Gradients

Liu

Chen

et al. 2021

Coatings

View full text Add to dashboard Cite

The purpose of this paper is to study the thermal shock resistance and failure mechanism of La2Ce2O7/8YSZ double-ceramic-layer thermal barrier coatings (LC/8YSZ DCL TBCs) under extreme temperature gradients. At high surface temperatures, thermal shock and infrared temperature measuring modules were used to determine the thermal cycling life and insulation temperature of LC/8YSZ DCL TBCs under extreme temperature gradients by an oxygen–acetylene gas flame testing machine. A viscoelastic model was used to obtain the stress and strain law of solid phase sintering of a coating system using the finite element method. Results and Conclusion: (1) Thermal cycling life was affected by the surface temperature of LC/8YSZ DCL TBCs and decreased sharply with the increase of surface temperature. (2) The LC ceramic surface of the failure coating was sintered, and the higher the temperature, the faster the sintering process. (3) Accelerated life test results showed that high temperature thermal cycling life is not only related to thermal fatigue of ceramic layer, but is also related to the sintering degree of the coating. (4) Although the high temperature thermal stress had great influence on the coating, great sintering stress was produced with sintering of the LC ceramic layer, which is the main cause of LC/8YSZ DCL TBC failure. The above results indicate that for new TBC ceramic materials, especially those for engines above class F, their sinterability should be fully considered. Sintering affects the thermal shock properties at high temperature. Our research results can provide reference for material selection and high temperature performance research.

show abstract

Mechanical and electrical characterisation of a phase transformation in thermal barrier coatings

Cited by 20 publications

References 47 publications

A comprehensive sintering mechanism for TBCs‐Part II: Multiscale multipoint interconnection‐enhanced initial kinetics

A comprehensive sintering mechanism for TBCs‐Part II: Multiscale multipoint interconnection‐enhanced initial kinetics

Growth modes for monoclinic yttria‐stabilized zirconia during the martensitic transformation

LC/8YSZ TBCs Thermal Cycling Life and Failure Mechanism under Extreme Temperature Gradients

Contact Info

Product

Resources

About