A phase-inversion casting process for preparation of tubular porous alumina ceramic membranes

In this study, a phase-inversion casting method with the self-designed forming mold and preparation route was proposed for preparation of tubular ceramic membranes. Thermal and sintering behaviors of as-prepared green tubular membranes were investigated. The results show that the significant weight loss occurs between 400 and 600 °C and three shrinkage stages appear in sintering process. Pore size distribution, image analysis, porosity, mechanical strength and gas flux were also studied to characterize the fabricated ceramic membranes. SEM images illustrate that the tubular membrane has a nearly homogeneous microstructure with good pore interconnect and uniform pore dispersion. With increasing of sintering temperature from 1500 to 1600 °C, the porosity decreases from 51.2 to 45.1% and the average pore size from 0.79 to 0.71 μm, while the flexural strength increases from 22.2 to 41.5 MPa. All these properties clearly suggest the practicability of the phase-inversion casting process to prepare tubular ceramic membranes.