Diffusion Kinetics of Oxygen in [beta]-Titanium Measured by Molten Flux Method

[...] calcium and titanium do not form any intermetallic compound, and the solubility of calcium in β-Ti (body-centered-cubic) is about 60 mass ppm at 1273 K.[10] In the present study, the commercial pure titanium (0.055 mass pet C-0. 14 mass pet Fe-0.32 mass pet O-0.006 mass pet N) was reacted with the Ca-CaCl^sub 2^ flux at 1273 through 1573 K. The interfacial concentration of oxygen is determined by the activity of Ca and CaO in the Ca(CaO)-CaCl^sub 2^ flux at given temperatures. [5], it is known that the oxygen content in Ti is proportional to the activity of CaO but inversely proportional to the activity of Ca in the flux as well as the activity coefficient of oxygen in Ti. [...] we determined the composition of the molten flux in order to control the concentration of oxygen in titanium based on the thermodynamic conditions involving activities of Ca and CaO.