Reaction bonding of silicon carbides by Binder Jet 3D-Printing, phenolic resin binder impregnation and capillary liquid silicon infiltration

Fabrication process of Reaction Bonded Silicone Carbides (RBSC) including Binder Jet (BJ) 3D-Printing, additional carbonization by Phenolic Resin Binder Impregnation (PRBI) and Capillary Liquid Silicon Infiltration (CLSI) has been examined. An effect of additional carbonization by PRBI of BJ 3D-printed porous SiC on the residual Si content after the CLSI and on the microstructure of secondary SiC has been investigated. It has been shown that 50% of the required carbon content can be obtained by this carbonization method in the BJ 3D-printed porous "green" body before the CLSI. The method of additional carbonization allows significant decreasing of the residual silicon content. High efficiency of the CLSI for full filling of complex geometric thin-walled shapes has been confirmed experimentally. This three-steps technology allows fabricating of the RBSC of complex geometric shapes with the wall thickness less than 1 mm and the residual Si less than 10-15%.