The application of nuclear techniques to high temperature oxidation studies

The¹⁸O(p, α)¹⁵N reaction has been used to determine the¹⁸O distribution in the oxides of a number of alloys which have been oxidised sequentially in natural gas and¹⁸O-labelled gas. A significant feature of all the cases investigated is the penetration of¹⁸O into the oxide formed previously in the natural gas. This penetration may occur in various ways and would be difficult to study by other techniques. The evidence presented here shows that there are subtle differences in oxidation behaviour and confirms that penetration of oxygen is a feature in the oxidation of alloys in which the predominant mechanism is transport of cations. This may have implications in explanations given to account for oxidation kinetics and adhesion and buckling of scales.