On the mechanism of internal oxidation in platinum–zirconium alloys: A TEM study

Internal oxidation of platinum–zirconium alloys has been studied using scanning and transmission electron microscopy. Nucleation sites of internal oxides are identified and different oxide particle morphologies are characterised. It is shown that the migration of grain boundaries during the internal oxidation process plays an important role concerning the oxide distribution and morphology. Coalescence of oxides in grain boundaries and inside the grains is described qualitatively. A consistent view of the internal oxidation of platinum–zirconium alloys based on grain boundary migration controlled internal oxidation is presented.