Comparison Between the Oxidation Behaviors of Ti6242S, Ti6246, TiXT Alloys, and Pure Titanium

Isothermal oxidation tests were performed on Ti6242S (Ti-6% Al-2% Sn-4% Zr-2% Mo, 0.08% Si), Ti6246 (Ti-6% Al-2% Sn-4% Zr-6% Mo, 0.05% Si), TiXT (Ti-0.45% Si) alloys and pure titanium in laboratory air at 560 degrees C, 600 degrees C and 650 degrees C for 1000 h to compare their oxidation behaviors. This study aims to highlight the role of molybdenum and silicon in the oxidation resistance of titanium alloys. The results show that 6 wt.% of Mo in Ti6246 alloys does not substantially change the oxidation behavior compared to Ti6242S alloy containing only 2 wt.% of Mo. Meanwhile, the presence of 0.45 wt.% Si seems to be clearly beneficial for the oxidation resistance, reducing the parabolic rate constant by a factor larger than 2 as compared to pure titanium.