Shrinkage

Crystallization

Engineering

Ceramic

Composite material

Flexural strength

Materials science

Stereolithography

Quartz

Cristobalite

Chemical engineering

Journal of Advanced Ceramics

Silica ceramic cores have played an important part in the manufacture of hollow blades due to their excellent chemical stability and moderate high-temperature mechanical properties. In this study, silica-based ceramics were prepared with Al 2 O 3 addition by stereolithography, and the influence of Al 2 O 3 content on mechanical properties of the silica-based ceramics was investigated. The Al 2 O 3 in silica-based ceramics can improve the mechanical properties by playing a role as a seed for the crystallization of fused silica into cristobalite. As a result, with the increase of Al 2 O 3 content, the linear shrinkage of the silica-based ceramics first decreased and then increased, while the room-temperature flexural strength and the high-temperature flexural strength first increased and then decreased. As the Al 2 O 3 content increased to 1.0 vol%, the linear shrinkage was reduced to 1.64% because of the blocked viscous flow caused by Al 2 O 3 . Meanwhile, the room-temperature flexural strength and the high-temperature flexural strength were improved to 20.38 and 21.43 MPa with 1.0 vol% Al 2 O 3 , respectively, due to the increased α-cristobalite and β-cristobalite content. Therefore, using the optimal content of Al 2 O 3 in silica-based ceramics can provide excellent mechanical properties, which are suitable for the application of ceramic cores in the manufacturing of hollow blades.

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