Determining Interface Fracture Toughness in Multi Layered Environmental Barrier Coatings with Laser Textured Silicon Bond Coat

In the high temperature combustion atmosphere inside of aircraft turbines, currently used ceramic matrix composites require a protective environmental barrier coating (EBC) to mitigate corrosion turbine parts. Besides thermomechanical and thermochemical properties like matching thermal expansion coefficient (CTE) resistance against corrosive media, mechanical adhesion strength are also necessary for long lifetime EBC. present work, between an air plasma sprayed silicon bond coat vacuum ytterbium disilicate topcoat was aimed be enhanced by laser surface structuring Si coat. An increase in interface toughness assumed, since introduction structures would lead increased interlocking at rougher interface. The measured new testing method, which allows specific interfaces. results demonstrate clear from original coat/topcoat (8.6 J/m2) compared structured (14.7 J/m2). Observations crack propagation indicates that may have led strengthening upper area sintering. Furthermore, addition cohesive failure components, adhesive components can observed, could influenced determined toughness.