Preparation of ceramic membranes on porous Ti-Al alloy supports by an in-situ oxidation method

In this study, ceramic/Ti-Al alloy composite membranes were prepared by an in-situ oxidation method. Oxidation temperature had a significant effect on the microstructure of the ceramic membrane, with ceramic membrane thickness increasing and pore size decreasing as the oxidation temperature was varied from 650°C to 900°C. This outcome was confirmed by scanning electron microscope (SEM) images that showed an increase in ceramic membrane thickness with an increase in oxidation temperature. Results from X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) studies indicated that a ceramic layer consisting of a mixture of amorphous Al₂O₃ and rutile TiO₂ was formed after oxidation at different temperatures. For an oxidation treatment of 750°C for two hours, the most frequent pore size of the ceramic/Ti-Al alloy composite membranes was 0.44μm. The weight and nitrogen flux of the membranes showed no observable change after ultrasonic treatment, indicating that ceramic/Ti-Al alloy composite membranes maintain good stability.