Abstract:The thermodynamics of interactions between various oxides (CaO, MgO, Al₂O₃ and Y₂O₃) and molten Ti and Ti alloys was investigated. The dissolution mechanism of oxides in molten Ti alloys was provided and the stability of oxides in molten Ti alloys was investigated and predicted by thermodynamic analysis. Interactions between oxides and Ti−Al melts were studied by oxide crucible melting experiments. By quantitative analysis, it is indicated that impurity contents in alloys are proportionally decreased with increasing the Al content in alloys and decreasing the melt temperature, which is in agreement with the results of the predicting thermodynamic stability.

Key words: Ti alloys; thermodynamics; oxide ceramics; interaction