Enhanced properties of silica-based ceramic cores by controlled particle sizes of cristobalite seeds

Abstract

In this work, cristobalite seeds were doped in silica-based ceramic cores, and the effect of particle size on the properties of ceramic cores was investigated. With decreasing particle size of the cristobalite seeds, the content of crystallised cristobalite in the sintered ceramic cores increased gradually due to the elevated surface area; the linear shrinkage, bulk density and leachability exhibited drastic increase after gradual decrease, and the flexural strength displayed an opposite tendency. When the mean particle size of cristobalite seeds is 5 μm, the ceramic cores showed optimal comprehensive properties, including linear shrinkage of 0.35%, apparent porosity of 31.2%, leachability of 0.31 g min −1 , creep deformation of 0.12 mm, and flexural strength of 23.5 MPa at home temperature and 26.0 MPa at 1550°C, which well meets the need of ceramic cores for hollow turbine blades. This work may provide new guidance for enhanced properties of silica-based ceramic cores.

Influence of Al2O3 content on mechanical properties of silica-based ceramic cores prepared by stereolithography

“…In addition, the high-temperature strength and room-temperature strength of 3D-printed silica ceramics are rarely investigated at the same time, which may have a strong influence on the performance of ceramic cores. At present, the reinforcements in silica ceramics, such as cristobalite [27] or silicon carbide [4], can improve the mechanical properties effectively by promoting the development of cristobalite. Furthermore, Al 2 O 3 has a fairly high flexural strength of 472 MPa [28] and thus contributes to enhancing the flexural strength of silica ceramics.…”

Influence of Al2O3 Content on Mechanical Properties of Silica-based Ceramic Cores Prepared by Stereolithography

“…In addition, the high-temperature strength and room-temperature strength of 3D-printed silica ceramics are rarely investigated at the same time, which may have a strong influence on the performance of ceramic cores. At present, the reinforcements in silica ceramics, such as cristobalite [27] or silicon carbide [4], can improve the mechanical properties effectively by promoting the development of cristobalite. Furthermore, Al2O3 has a fairly high flexural strength of 472 MPa [28] and thus contributes to enhancing the flexural strength of silica ceramics.…”