High-temperature oxidation of Cu–Ti-based rapidly solidified alloys

Abstract The high-temperature oxidation of two Cu–Ti-based alloys (Cu50Ti50 and Cu50Ti40Al10) produced by rapid solidification was studied in air and in pure oxygen atmosphere by thermogravimetry, X-ray diffraction and electron microscopy. In the temperatures range 650°C ≤ T ≤ 750°C the growth of the oxide film is generally diffusion-controlled and its kinetics can be mostly described with parabolic rate law. At lower temperatures (e. g. T = 600°C) the oxidation reveals cubic kinetics law for both alloys. The two alloys show the same oxidation rate for T 800°C), Cu50Ti40Al10 reveals a higher oxidation resistance. The main oxidation product for both alloys in air as well as in pure oxygen (600–750°C) is TiO2 (rutile) from the beginning of the reaction. Oxygen dissolves and diffuses through the oxide and reacts with Ti, counter-diffusing from the bulk of the matrix to the matrix/oxide inter...