Processing of TiC-Al2O3 Powders

Abstract

In this study, the formation of TiC-Al2O3 ceramic composite powders has been investigated using a powder mixture of TiO2, Al and C by the aluminothermic method. Thermal analysis (TG/DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods were used for the characterisation of the starting and the processed samples. It was found that the two exothermic peaks, as a twin peak, were observed on the DTA curve of the mixture after aluminium melted, which indicated the reduction of TiO2 by molten aluminium. A further increase in temperature of up to 950˚C in the second exothermic peak was observed and was related to the formation of TiC by the in-situ reaction of Ti with C. X-ray diffraction was confirmed, the processed sample phases were Al2O3 and TiC, depending on the reaction temperature and time. The determined phases in the starting composition disappeared in the processed samples. With the increase in temperature, the conversion of TiO2 to Ti, the formation of TiC and the formation of Al2O3 occurred during the process.

Keywords: Titanium carbide, aluminothermic process, thermal analysis, alumina