High-temperature behaviour of Ti–Al–Si alloys produced by reactive sintering

Alloys formed by Ti–Al intermediary phases have low density and very good high-temperature oxidation resistance. Further improvement of high-temperature behaviour can be achieved by a suitable addition of silicon. In this work, Ti–Al–Si alloys containing 20 wt.% of aluminium and 10–20 wt.% of silicon produced by a reactive sintering technology were tested. Isothermal oxidation tests were carried out at 1000 °C in air. The oxidation rate was determined from weight gains caused by oxide formation. Microstructure and phase composition of the oxide layers were studied. Microstructure and hardness changes after various annealing durations were described.