Fabrication of Fe-Al lntermetallic/TiC-Al_2O_3 Ceramic Composites from llmenite by Reaction Sintering

摘要

Fe-Al intermetallic/TiC-Al_2O_3 ceramic composites were fabricated by in-situ carbothermic and aluminothermic reduction from natural ilmenite. Synthesis and sintering of the composites were accomplished unanimously in the vacuum hot pressure furnace. The thermodynamic process, the composition, the microstructure as well as the properties of the FeTiO_3-Al-C system were studied in detail through theoretical analysis and experimental research. It was shown that the synthesis process started from the melting aluminium, followed by the deoxidation of ilmenite step by step via a series of different valent titanium oxides to form TiC, Al_2O_3 and Fe-Al as the ultimate productions. The particle sizes are mostly 3-5μm, and their distributions are uniform. Meanwhile, the addition of additives can improve the wettability of alloy to ceramic phases and the combination of the interfaces, giving rise to the properties of the composites as a whole.