Effect of B4C on co-sintering of SiC ceramic membrane

Abstract

A SiC ceramic membrane was successfully fabricated at 2200 °C by a co-sintering process through the addition of B4C powder. The support and membrane with a pore size of 34.92 µm and 9.93 µm were prepared with coarse SiC powder (~120 µm) and spheroidized SiC powder (~22 µm), respectively. The interface between the support and membrane was distinct and particles were closely bonded to each other. The addition of 1.5 wt% B4C can decrease the sintering temperature of support from 2350 to 2200 °C, which had a good match with that of membrane. The mechanism for promoting the sintering of support is that B4C dissolved into the SiC lattice and increased the crystal defects. The bending strength of the support and the membrane was 38.77 MPa and 32.15 MPa, respectively. The nitrogen gas flux and gas permeability of the SiC ceramic membrane was 19,406 m3/m2 h bar and 5.817 × 10–12 m2.