Mechanical properties and oxidation behavior of the Ti-24Al-14Nb-3V-0.5Mo alloy sheet

Tensile properties of the Ti-24Al-14Nb-3V-0.5Mo alloy (at.%) solution treated at 1000 degrees C after hot-rolling was studied in the temperature range between room temperature and 700 degrees C. The tensile strength was sensitive to the test temperature and was decreased as the temperature increased from 200 to 500 degrees C. Tensile strength of the alloy at room temperature initially increased gradually with an increase in the strain rate from 8.3 x 10(-4) to 0.33 s(-1) followed by a slow hardening with increasing the strain rate to 8.3 x 10(-1) s(-1). The alloy exposed at 700 degrees C showed the best oxidation resistance due to the formation of a continuous alpha-Al2O3 layer in the scale. However, the beneficial doping effect of Nb addition on the oxidation resistance above 700 degrees C was probably overlaid by fast internal diffusion of oxygen, which was proved by a thick transitional layer beneath the scale in the specimen exposed at 800 degrees C. (c) 2006 Elsevier B.V. All rights reserved.