Additive manufacturing of silicon carbide for nuclear applications

Abstract

Additive manufacturing (AM) is a rapidly evolving technology being considered for nuclear applications. A special focus on AM to fabricate nuclear-grade silicon carbide (SiC) is explored in this paper. First, we present currently available AM processing options for SiC. AM methods commonly used for other ceramics, in which the feedstocks are forms of polymers, powders, and/or reactive chemical vapors, are also applicable to SiC. SiC phases are formed by pyrolysis of pre-ceramic polymer, direct reaction of powder precursors, sintering of SiC powders, or chemical vapor deposition/infiltration. Second, we discuss how the different microstructures of SiC materials fabricated by various processing methods affect their behavior in nuclear environments. Third, we discuss state-of-the-art AM technologies for the fabrication of relatively pure SiC, which show great potential to retain its strength under neutron irradiation: (1) binder jet printing followed by chemical vapor infiltration, (2) laser chemical vapor deposition, and (3) selective laser sintering of SiC powders.