Determination of strength properties for yttria stabilised zirconia coatings

Abstract

The mechanical properties of coatings are significantly influenced by their interfacial bonded status and interfacial stresses, which are quite difficult to measure by traditional testing techniques. In this study, a series of theoretical analyses regarding Young's modulus, interface shear stress and tension stress for coatings are successfully deduced based on an assumption of interfacial constraints and homogeneous strain. Three equations are derived to determine the Young's modulus, interface shear strength and cohesion strength for coatings. A tension method is used to test the mechanical properties of coatings and presented in detail. It concludes that this method is relatively simple to perform, and allows for a reliable determination of interface shear strength and cohesion strength for coatings. A corresponding theoretical analysis is logical and reasonable. The magnitude of the Young's modulus, interface shear strength and cohesion strength for yttria stabilised zirconia coatings was about 171–189, 6–24 and 175–238 MPa respectively.