Accuracy of Young’s Modulus of Thermal Barrier Coating Layer Determined by Bending Resonance of a Multilayered Specimen

Waki, Hiroyuki; Takizawa, Kensuke; Kato, Masahiko; Takahashi, Satoru

doi:10.1007/s11666-016-0399-3

Cited by 9 publications

(2 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They also observed that the coating failure occurred at higher stresses when subjected to compressive loading. Mechanical properties of TBCs were also measured by non-destructive resonance techniques [17,18]. The values obtained were not too different from the values reported previously by beam bending techniques.…”

Section: Beam Bendingmentioning

confidence: 69%

Stiffness of Plasma Sprayed Thermal Barrier Coatings

Paul¹

2017

Coatings

View full text Add to dashboard Cite

Thermal spray coatings (TSCs) have complex microstructures and they often operate in demanding environments. Plasma sprayed (PS) thermal barrier coating (TBC) is one such ceramic layer that is applied onto metallic components where a low macroscopic stiffness favors stability by limiting the stresses from differential thermal contraction. In this paper, the Young's modulus of TBC top coat, measured using different techniques, such as four-point bending, indentation and impulse excitation is reported, along with a brief description of how the techniques probe different length scales. Zirconia-based TBC top coats were found to have a much lower global stiffness than that of dense zirconia. A typical value for the as-sprayed Young's modulus was~23 GPa, determined by beam bending. Indentation, probing a local area, gave significantly higher values. The difference between the two stiffness values is thought to explain the wide range of TBC top coat Young's modulus values reported in the literature. On exposure to high temperature, due to the sintering process, detached top coats exhibit an increase in stiffness. This increase in stiffness caused by the sintering of fine-scale porosity has significant impact on the strain tolerance of the TBC. The paper discusses the different techniques for measuring the Young's modulus of the TBC top coats and implications of the measured values.

show abstract

Section: Beam Bendingmentioning

confidence: 69%

Stiffness of Plasma Sprayed Thermal Barrier Coatings

Paul¹

2017

Coatings

View full text Add to dashboard Cite

show abstract

“…Several techniques, including beam bending [6][7][8][9][10][11][12][13][14], impulse excitation [15][16][17][18], compression [19][20][21][22], and indentation [6,8,[11][12][13][14][23][24][25][26][27], have been developed for measuring the elastic properties of the APS TBCs. The elastic moduli reported in the literature, however, vary over a broad distribution: extending from a value as low as 0.72 GPa to over 150 GPa [6-10, 15-25, 27-29].…”

Section: Introductionmentioning

confidence: 99%

Measurements and understanding of the stiffness of an air plasma sprayed thermal barrier coating

Chen

Zhao

et al. 2020

Surface and Coatings Technology

View full text Add to dashboard Cite

In this work, the stiffness of an air plasma sprayed thermal barrier coating (APS TBC) was studied using the three-point bending technique. Various measurements over different time periods were made on detached TBC beams, prepared by acid etching, in both as-deposited states and after heat treatment. Monotonic and cyclic loading were conducted to understand the mechanical behaviour of the TBCs in detail. The TBC beams during bending show nonlinear behaviour, inelastic deformation and hysteresis loops. The derived global in-plane elastic modulus, at first increases and then decreases with thermal exposure, and is of the range 14-18 GPa. This behaviour is a result of competition between sintering and development of microstructural damage. Direct microstructural observations during In-situ mechanical testing show that intra-splat opening/closure and inter-splat sliding give rise to the relatively low elastic modulus of the APS TBC.

show abstract