Determination of interfacial properties of thermal barrier coatings by shear test and inverse finite element method

Abstract Thermal barriers made up by a ceramic top coating and a metallic bond coating are subjected to thermal cycles in service. The thermal stresses vary during the cycles and the residual stresses change as a result of plastic flow and creep. The stress state in thermal barrier coatings during a thermal cycle has been examined with a finite element method using temperature dependent material data. The calculated results were verified by measurements of the residual stresses with the layer removal technique before and after cycling of specimens heated in furnace with air environment. According to the simulation of a thermal cycle to 700 ° C, using a finite element method, the bond coat is approximately stress free after 1 hour dwell time. Thus, the residual stresses after a thermal cycle is a result of thermal expansion mismatch and temperature drop.

Download Full-text

Effect of five kinds of pores shape on thermal stress properties of thermal barrier coatings by finite element method

Ceramics International ◽

10.1016/j.ceramint.2017.04.139 ◽

2017 ◽

Vol 43 (13) ◽

pp. 9664-9678 ◽

Cited By ~ 11

Author(s):

Ming Yang ◽

Yongping Zhu ◽

Xueying Wang ◽

Shengnan Guo ◽

Jing Hu ◽

...

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Thermal Stress ◽

Thermal Barrier Coatings ◽

Thermal Barrier ◽

Barrier Coatings ◽

Element Method

Download Full-text

Investigation about Thermal Shock Property of Plasma-Spraying Sm2Zr2O7 Thermal Barrier Coatings with Different Substrate Condictions

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.354-355.145 ◽

2011 ◽

Vol 354-355 ◽

pp. 145-148

Author(s):

Hong Song Zhang ◽

Hong Chan Sun

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Thermal Expansion ◽

Residual Stresses ◽

Plasma Spraying ◽

Thermal Barrier Coatings ◽

Thermal Barrier ◽

Shear Stresses ◽

Substrate Thickness ◽

Barrier Coatings

Effect of substrate conditions, including material type, thickness and radius of substrate, on thermal-shocking stresses of plasma spraying Sm2Zr2O7/ NiCrCoAlY TBCs was analyzed through finite element method. Results show that radial stresses decrease with time increasing, and they decrease with the increasing of distance from center to edge along radius. However, axial residual stresses increse abruptly at the edge of specimen. All residual stresses increse with incresing of thermal expansion coefficient of substrate. Radial stresses increase with substrate thickness increasing, however, they are not effectd by substrate thickness if it is great than 20mm.and axial residual stresses and shear stresses are not effected by the substrate thickness. The maximum values of axial stresses and shear stresses were not effected by sustrate radius. and values of radial stresses remian invariable when substrate radius is over 18mm.

Download Full-text

Relation between Concave Cone 3 Dimension Topography and Residual Stress in Thermal Barrier Coatings

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.291-294.172 ◽

2011 ◽

Vol 291-294 ◽

pp. 172-175

Author(s):

Zhi Yong Han ◽

Huan Wang

Keyword(s):

Finite Element Method ◽

Residual Stress ◽

Finite Element ◽

Compressive Stress ◽

Thermal Barrier Coatings ◽

Thermal Barrier ◽

Barrier Coatings ◽

Barrier Coating ◽

Stress Changes ◽

Unit Stress

Considering the concave cone 3 dimension interface topography unit, the distribution of residual stress in thermal barrier coating was calculated using ABAQUS soft by finite element method. The calculating result shows that the residual stress is affected by interface topography unit obviously. Compressive stress exists in concave cone topography unit. Stress concentrates in boundary of topography unit and reaches maximal value at the lowest place of the topography. Compressive stress changes with the size of topography unit and the space between two topography units distinctly.

Download Full-text