Quantification and kinetics of nitrogen mass gain during high temperature oxidation of titanium in air

Improving the high-temperature oxidation resistance of titanium alloys in air is a prerequisite for extending their use in turbojet engines. A better understanding of the role of atmospheric nitrogen is required for this purpose. Here, we studied the insertion kinetics of nitrogen in titanium at 650 °C in air up to 100h. Moreover, the nitrogen mass gain, and its ratio over the total mass gain, were quantified as a function of the oxidation duration by using Nuclear Reaction Analysis. It was found that nitrogen inserts into titanium with a parabolic kinetics and a rate constant about 1500 times smaller than oxygen.