Coatings of ceramics on metals.

An improved understanding of the complexity of the chemical bond theory as it applies to multiphase alloys is developing. A better understanding of compatibility of alloy and ceramic during refiring schedules based upon leucite phase transformations and the ramifications for porcelain failure is emerging. It may also be possible to use other high-expansion glass-ceramic compositions for coating metals. The limitations of bond test methods have been identified. Future bond test methods should aim to make use of fracture toughness theory. Ideally, it should be possible to specify ceramic-to-metal interfacial fracture toughness as a percentage of the fracture toughness of the ceramic interface material. Wet chemical methods have the potential to produce a number of innovative advances in new ceramic and glass biomaterials. These systems may provide a useful method for initial ceramic precoats on metals.