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Numerical simulation of thermal barrier coating system under thermo-mechanical loadings

Moridi, A ; Sharif University of Technology | 2011

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  1. Type of Document: Article
  2. Publisher: 2011
  3. Abstract:
  4. In the present paper, numerical simulation of thermal barrier coating system under thermo-mechanical loadings is performed, using the finite element method in ABAQUS software. The base material is Aluminum-silicon alloy, A356.0 which is widely used in automotive components such as diesel engine cylinder heads. Thermal barrier coatings (TBCs) are applied to combustion chamber in order to reduce fuel consumption and pollutions and also improve fatigue life of components. The roughness effect of coating layers on stress distribution of test specimens is investigated. Semi-ellipsoid roughness of the interfaces between substrate/bond coat and bond coat/top coat are simulated to get the stress distribution by considering different wave lengths and roughness amplitudes. Mutual influence of waves positioning (in phase and out of phase) is also studied in present investigation. Results show that separation of the TBC system from substrate (in cylinder heads application) is more probable than separation of BC and TC due to higher stresses in substrate/BC interface. Moreover the magnitude of stress increases when the roughness amplitude enhances and wave length shortens which leads to crack initiation in TBC system. Crack propagation and failure in TBCs accelerate when the peak regions of asperities position on each other, leading to more tensile zones in BC layer
  5. Keywords:
  6. Roughness profile ; ABAQUS software ; Aluminum silicon alloys ; Automotive component ; Base material ; Bond coats ; Coating layer ; Cylinder head ; In-phase ; Out of phase ; Roughness amplitude ; Roughness effects ; Semi-ellipsoid ; Test specimens ; Thermal barrier ; Thermal barrier coating systems ; Thermo-mechanical loading ; ABAQUS ; Coatings ; Combustion chambers ; Computer simulation ; Computer software ; Cracks ; Diesel engines ; Engine cylinders ; Finite element method ; Loading ; Numerical methods ; Silicon alloys ; Stress analysis ; Stress concentration ; Superalloys ; Thermal conductivity ; Thermal barrier coatings
  7. Source: Proceedings of the World Congress on Engineering 2011, WCE 2011, 6 July 2011 through 8 July 2011 ; Volume 3 , July , 2011 , Pages 1959-1964 ; 9789881925152 (ISBN)
  8. URL: www.iaeng.org/publication/WCE2011/WCE2011_pp1959-1964.pdf