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

• 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.

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 30 vol% solid content possessing roughly 40 MPa flexural strength and 50 vol% 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.