Effects of Fe doping on preparation of Ti-Si porous membrane via in-situ reactive process

Abstract

Asymmetric porous filter element can reach a high filtering accuracy with larger filtration flux, which can enhance the filtration efficiency and reduce the energy consumption when it was applied in separation equipment. A novel porous material of Ti-Si intermetallic compound micro-porous membrane was successfully synthesized with Fe doped Ti mixed powder and SiO2 by the in-situ reactive sintering process. Effects of Fe doping, sintering temperature and the external load pressure on the formation of membrane were systemically studied. The results show that increasing Fe doping amount can celebrate the in-situ reactive process and promote the membrane formation. The synthesized granules on the membrane are well distributed with the size of 1∼3 µm, and the thickness of the membranes is 4∼7 µm. The relative air permeability coefficient of porous membrane reduces raptly with increasing either Fe doping amount, or sintering temperature and the external load pressure. All synthesized membranes show the presence of Ti5Si3 and Ti phases, with a little amount phase of FeTi and FeO. The membrane formation mechanism is due to the large reduction reactivity of Fe doped Ti powder with SiO2, and the asymmetric porous structure of Ti5Si3/Ti was obtained finally.