Additive manufacturing (AM) of ceramics is an extensively grown field with very promising opportunity to produce advanced ceramic components in more cost-efficient way, compared to traditional processes. Binder Jetting (BJ) is one of the most promising techniques to print ceramic green bodies. In order to reach full dense parts, such processes as sintering and/or infiltration are required. Reaction bonded SiC (RB-SiC) was successfully produced by BJ printing followed by additional enrichment of green body with free carbon and then Liquid Silicon Infiltration (LSI). Basically, the resulting product is a composite material that consists of SiC primary particles, SiC produced by reaction between free carbon and liquid Si, and residual Si. Its and final properties depend mainly on amount of residual Si.
The presented study focused on improvement of density of BJ SiC as- printed green body by infusion assisted method based on use of different slurries containing SiC submicron and nanoparticles. As a result, the density of the green samples was improved by 23-52%. The microstructure of the green samples and the samples after LSI was studied by SEM, HR-SEM. The presence of SiC submicron and nanoparticles was found in the green body, as well as almost homogeneous distribution of submicron SiC particles was revealed in the microstructure of the samples after LSI. It was found that primary SiC particles and submicron SiC particles created hierarchical composite microstructure based on SiC particles from tens of microns and submicron SiC particles well dispersed in Si matrix. This phenomenon opens possibilities to combine properties from nanoscale and micron scale sizes in one material. Some basic properties of the resulting material, like modulus of elasticity, Poisson's Ratio, microhardness, as well as content of phases into the microstructure, were examined.