The influence of gel-casting parameters on the preparation of Si porous bodies

This study aimed to investigate and optimise the rheological behaviour and gel-casting parameters of Si suspensions prepared to fabricate RBSN bodies. Si green bodies with 30vol% solid content possessing roughly 40MPa flexural strength and 50vol% porosity. The gelation time decreases by heating, and the Si gel-cast body dried in PEG1000 solution shows less than 2% shrinkage. Based on FESEM analysis and adsorption-desorption of nitrogen gas, the final Si bodies show open pores and uniform distribution. •Mixing time strongly affects the rate of silica formation and hydrogen release.•The way of gelation influences the quality and shrinkage of the Si GC body.•Using desiccant solution for drying process prepares the body free of crack and warpage.