Oxidation of Laminated Ta/TiAl(Si)C Composites in the Temperature Range 800-1300°C

The paper presents the results of a study of high-temperature oxidation in air of the metal-ceramic layered TiAl(Si)C/Ta composites. The composites were made of pre-ceramic papers filled with TiAl(Si)C and metal foils (Ta) by spark plasma sintering. The sintering temperature was 1250°C, the holding time was 5 min, and the pressure was 50 MPa. The corrosion resistance of the laminated TiAl(Si)C/Ta composites was estimated based on the results of high-temperature oxidation in air. The phase composition and microstructure of the oxide layers were analyzed by X-ray diffraction and scanning electron microscopy, respectively. It has been found that the TiAl(Si)C/Ta composites demonstrate high oxidation resistance in the temperature range 800–1200°C due to the formation of a dense AlO layer on the outer surface of TiAl(Si)C. With an increase in the oxidation temperature to 1300°C, a complex oxide layer is formed, consisting of an outer TiO/SiO/AlTiO layer and an inner TiO/AlO oxide layer. The thickness of the TiO/AlO oxide layers formed on the surface of the TiAl(Si)C/Ta composite at oxidation temperatures up to 900°C is less than 1 μm, at a temperature of 1200°C the thickness of the oxide layers is 3.5 μm, and at 1300°C it is 56 μm.