Effect of TGO topography on TBCs residual stresses

By using nonlinear finite element model, the residual stress distribution which was affected by interface topography of top ceramic coat(TCC), bond coat(BC) and thermally-growth oxide(TGO) interface area in thermal barrier coatings(TBCs) system was calculated.In the process of calculation, thermodynamic parameters of TCC, TGO and BC were considered.The calculating results show that the residual stress of TGO interface is affected by interface topography unit size and topography distribution density obviously.The stress on TCC/TGO interface is greater than that on BC/TGO interface.Stress concentrates at the tip of cone topography center and reaches the maximum value, which becomes the dangerous point for failure of thermal barrier coatings system.The residual stress level decreases with the increasing of topography quantity.