Oxidation behavior and effect of oxidation on tensile properties of Ti60 alloy

Oxidation behavior of a near-alpha Ti60 titanium alloy was investigated in the temperature range of 600-750 A degrees C for up to 100 h exposure. The results showed that the oxidation kinetics of Ti60 alloy followed parabolic kinetics below 700 A degrees C but parabolic-linear kinetics above 700 A degrees C. The total activation energy was calculated to be 256 kJ/mol over the whole temperature range. The oxidation products were TiO2 after thermal exposure at 700 A degrees C for 100 h, but a mixture of TiO2 and a small amount of Al2O3 for the specimens oxidized at 750 A degrees C for 50 h. The grain boundaries were preferred sites for oxidation products formation during the oxidation. The tensile tests were performed at room temperature for specimens before and after oxidation. Both of the strength and ductility decreased for the specimens with oxide scale. However, both of them increased when the oxide scale was removed before testing.