Increasing the silicon carbide content in laser sintered reaction bonded silicon carbide

Additive manufacturing (AM) of ceramics is in its infancy. Compared to conventional shaping processes, AM is more economical for small series and comes with a higher degree of design freedom. AM technologies like laser sintering can be used to produce preforms for reaction bonded silicon carbide (RBSC) parts. After laser sintering, liquid silicon infiltration is carried out and the preforms are transformed into dense RBSC parts, also known as Si-infiltrated SiC (SiSiC). These parts, however, contain residual Si which has a detrimental effect on mechanical and thermal properties. The current work focusses on creating an RBSC component with high SiC and low residual Si contents. This is done by impregnating the laser sintered preforms with a carbon precursor phenolic resin. The carbon provided by the resin reacts with the Si melt during infiltration to form a secondary (reaction formed) SiC. The result is a fully dense RBSC component with up to 75 vol% SiC.status: accepte