Bonding, structure, and properties of metal/ceramic interfaces: Part 2 Interface fracture behaviour and property measurement

The fracture behaviour of metal/ceramic interfaces is reviewed. It is shown that fracture is a complicated process which depends on many factors such as the geometry of the test specimen and loading conditions, strength of the interfacial bond, thermal, elastic, and fracture properties of the metal and ceramic, thickness of the metal layer, and testing environment. Considerable progress has been made in understanding some of these areas while others are just beginning to be understood. Advances in this field include the development of favourable specimen geometries for measuring various interface properties and an understanding of the relationship between the phase angle of loading, the crack trajectory, and the interface fracture energy for these geometries. The major contributions of plasticity and crack bridging to the fracture resistance of metal/ceramic interfaces has been established. The detrimental effects of thermal and elastic mismatch on interface properties are also well known. Conversely, little is known about the stress corrosion and fatigue behaviour of metal/ceramic interfaces though data on these time dependent failure modes are beginning to appear in the literature. Considerably more work is needed in order to understand the fracture behaviour of metal/ceramic interfaces.