Improved mechanical properties of SiC fiber reinforced silica-based ceramic cores fabricated by stereolithography

Abstract

• The SiC fiber reinforced silica-based ceramics were prepared via stereolithography. • Excellent high temperature mechanical properties were obtained by the reinforcement of SiC fibers. • SiC fiber can reduce the linear shrinkage of silica-based ceramics greatly through the oxidation reaction of SiC. • The manufacturing precision of ceramic parts is improved a lot. Silica-based ceramic cores have been widely used to fabricate aero-engine hollow blades due to their moderate high temperature mechanical properties and excellent leachability. In this study, silica-based ceramics with SiC fiber addition were prepared via stereolithography, and the influence of SiC fiber content on mechanical properties of the obtained silica-based ceramics was investigated. With the increase of SiC fiber content, linear shrinkage gradually decreased, while room temperature flexural strength and high temperature flexural strength first increased and then decreased. As SiC fiber content increased to 4.0 wt%, linear shrinkage was reduced to 0.62% resulting from the oxidation of SiC. Furthermore, room temperature flexural strength was improved from 11.79 MPa to 23.83 MPa and high temperature flexural strength was enhanced from 15.64 MPa to 34.62 MPa with 4.0 wt% SiC fiber addition due to the reinforcement of fibers and the enhanced β-cristobalite content, which meets the need of ceramic cores. Therefore, it demonstrates the capability of fabricating high-performance and high-precision silica-based ceramic cores reinforced by SiC fibers via stereolithography for rapid manufacturing of hollow blades.