2004 Volume 45 Issue 10 Pages 3065-3070
The interfacial characteristics between porcelain coating and titanium under vacuum firing at 800°C have not been well documented. The cross-sectional variations in microstructures and compositions at the porcelain/Ti interface were investigated with a SEM and an EPMA equipped with WDS. The phase constituents of the porcelain bulk coating and the nearby porcelain/Ti interface were analyzed by X-ray and thin-film X-ray diffractometry respectively. In addition, a TEM equipped with EDS was used to examine the porcelain/Ti oxide interface. The experimental results revealed that the oxidation of Ti occurred at the porcelain/Ti interface, and it is reasonable to deduce that the Ti reduces the SnO2 and SiO2 components of the porcelain and becomes Ti oxide. Furthermore, redox reactions and chemical bonding occur at porcelain/Ti interface during firing and thus prevent the initiation of fracture from occurring at this interface. Subsequently, the fracture initiation tends to be located near the interface of newly formed Ti oxide and Ti substrate and/or slightly inside the Ti.
