Fabrication of high-performance silica-based ceramic cores through selective laser sintering combined with vacuum infiltration

Abstract

Silica-based ceramic cores have been widely used for manufacturing aero-engine hollow blades due to excellent mechanical properties and chemical stability. In this study, selective laser sintering (SLS) based on 3D printing was combined with vacuum infiltration (VI) to fabricate silica-based ceramic cores. The influence of laser processing parameters and infiltration times on the mechanical properties of the silica-based ceramics was investigated. The results showed that the optimal SLS processing parameters were determined as 11 W, 2000 mm/s and 100 µm for the laser power, scanning speed and hatch space, respectively. Meanwhile, as the infiltration time increased to 120 min, the room temperature flexural strength was gradually improved to 7.45 MPa, while the linear shrinkage was constantly reduced to 0.60%, all due to the enhanced α-cristobalite and mullite content. Furthermore, the high temperature creep deformation and flexural strength at 1550 ℃ of the silica-based ceramics prepared with the optimal SLS processing parameters and infiltration time were 0.31 mm and 15.04 MPa, which meets the need of ceramic cores. Consequently, high-performance silica-based ceramic cores can be fabricated by SLS-VI for the rapid manufacturing of hollow blades.