Determiningtheinterfacialpropertiesofthermalbarriercoatings(TBCs)isimperativefortheirdurabilityevaluationandfurtherimprovements.Aceramiccoating(topcoat)andaNiCoCrALYbondcoatwereatmospheric-plasma-sprayed(APS)onastainlesssteelsubstrate.Amodifiedthree-pointbendingtestwasadoptedtoinitiateandpropagatethetopcoat/bondcoat(TC/BC)interfacialcrack.Afteracompletedelamination,thefracturesurfaceswereexaminedbyanopticalmicroscope,whichshowsthatthecrackingplanewasmerelyontheTC/BCinterface.Basedontheexperimentalresultsofload–displacementandcracklength–displacement,thestrainenergyreleaserateGforcrackpropagationwascalculated,andtheaveragedmagnitudewas77.1J/m2.Repeatableresultshaveindicatedthatthemethodcanbeusedfortheevaluationofinterfacialfracturetoughnessinthermalbarriercoatingsandothermulti-layerstructures.
