Journal of the American Ceramic Society, Vol.93, No.4, 1148-1155, 2010
Mechanisms and Kinetics of the Hydrothermal Oxidation of Bulk Titanium Silicon Carbide
Hydrothermal oxidation of bulk Ti(3)SiC(2) in continuous water flow was studied at 500 degrees-700 degrees C under a hydrostatic pressure of 35 MPa. The oxidation was weak at 500 degrees-600 degrees C and accelerated at 700 degrees C due to the formation of cracks in oxides. The kinetics obeyed a linear time-law. Due to the high solubility of silica in hydrothermal water, the resulting oxide layers only consisted of titanium oxides and carbon. Besides general oxidation, two special modes are very likely present in current experiments: (1) preferential hydrothermal oxidation of lattice planes perpendicular to the c-axis inducing cleavage of grains and (2) uneven hydrothermal oxidation related to the occurrence of TiC and SiC impurity inclusions. Nonetheless the resistance against hydrothermal oxidation is remarkably high up to 700 degrees C.