Title of article :
Effects of processing conditions on the mechanical properties and deformation behaviors of plasma-sprayed thermal barrier coatings: Evaluation of residual stresses and mechanical properties of thermal barrier coatings on the basis of in situ curvature mea
Author/Authors :
Xiancheng Zhang، نويسنده , , Makoto Watanabe، نويسنده , , Seiji Kuroda، نويسنده ,
Issue Information :
دوهفته نامه با شماره پیاپی سال 2013
Pages :
11
From page :
1037
To page :
1047
Abstract :
A modified analytical model has been developed to describe the nonlinear elastic response and residual stress in plasma sprayed thermal barrier coatings (TBCs) on the basis of the measured curvature–temperature plot during the spraying process. Evolution of residual stresses and the nonlinear stress–strain relation of the coating during the cooling stage after deposition were identified and the strain-dependent coating modulus was obtained. Wide ranges of deposition temperature from 200 to 850 °C as well as that of passage thickness from 6 to 58 μm were explored in the experiments because significant changes in the TBC microstructure could be expected. The analyzed results were related to the processing parameters in spraying, such as the substrate temperature and passage thickness. A complicated interplay among the coating microstructure, residual stresses and mechanical properties was identified. Generally with increasing deposition temperature or passage thickness, denser microstructures were observed with an increase in elastic modulus. The nonlinear strain–stress curves of TBCs indicated that the coating modulus increased with compressive residual stress due to closing of microcracks and inter-splat sliding. Moreover, the coating modulus depended not only on the magnitude of residual stress but also on the coating thickness and it was found that the axial force, which is the product of the residual stress and coating thickness, could be used to express their synergistic effect.
Keywords :
Thermal barrier coatings , Curvature measurement , Residual stress , Coating modulus , Analytical modeling
Journal title :
ACTA Materialia
Serial Year :
2013
Journal title :
ACTA Materialia
Record number :
1146766
Link To Document :
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