Interface fracture property of PEO ceramic coatings on aluminum alloy

This paper combines the four-point bending test, SEM and finite element method to study the interface fracture property of PEO coatings on aluminum alloy. The interface failure mode of the coating on the compression side is revealed. The ceramic coating crack firstly along the 45° to the interface, then the micro crack in the coating deduces the interface crack. The plastic deformation observed by SEM shows excellent adhesion property between the coating and substrate. The plastic deformation in the substrate is due to the interfacial crack extension, so the interface crack mode of PEO coatings is ductile crack. The results of FEM show that the compression strength is about 600 MPa.