SOLID-STATE REACTIONS AND PHASE-RELATIONS IN THE TI-SI-O SYSTEM AT 1373 K

Reactions between Ti and SiO2 were studied at 1373 K (1100 degrees C) under vacuum conditions using planar diffusion couples. A method to co rrect for the presence of surface oxide was developed which led to imp roved oxygen measurements with the electron probe microanalyzer. An is othermal section through the Ti-Si-O phase diagram at 1373 K was deter mined using measured diffusion paths and phase compositions in equilib rated alloys. The experimentally determined isothermal section was com pared to isothermal sections calculated using thermodynamic data. In a ddition the sequence of reaction layers formed in the diffusion couple s is discussed in terms of thermodynamic activity diagrams.