Electrolytic Production of Ti5Si3/TiC Composites by Solid Oxide Membrane Technology

This paper investigated the electrolytic production of Ti 5 Si 3 /TiC composites from TiO 2 /SiO 2 /C in molten CaCl 2 . The solid-oxide oxygen-ion-conducting membrane tube filled with carbon-saturated liquid tin was served as the anode, and the pressed spherical TiO 2 /SiO 2 /C pellet was used as the cathode. The electrochemical reduction process was carried out at 1273 K and 3.8 V. The characteristics of the obtained cathode products and the reaction mechanism of the electroreduction process were studied by a series of time-dependent electroreduction experiments. It was found that the electroreduction process generally proceeds through the following steps: TiO 2 /SiO 2 /C → Ti 2 O 3 , CaTiO 3 , Ca 2 SiO 4 , SiC → Ti 5 Si 3 , TiC. The morphology observation and the elemental distribution analysis indicate that the reaction routes for Ti 5 Si 3 and TiC products are independent during the electroreduction process.