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

Abstract

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 Al2O3 addition by stereolithography, and the influence of Al2O3 content on mechanical properties of the silica-based ceramics was investigated. The Al2O3 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 Al2O3 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 Al2O3 content increased to 1.0 vol%, the linear shrinkage was reduced to 1.64% because of the blocked viscous flow caused by Al2O3. 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% Al2O3, respectively, due to the increased α-cristobalite and β-cristobalite content. Therefore, using the optimal content of Al2O3 in silica-based ceramics can provide excellent mechanical properties, which are suitable for the application of ceramic cores in the manufacturing of hollow blades.

Vat photopolymerization 3D printing of Al2O3 ceramic cores with strip‐shaped pores by using polyamide 6 fiber template

“…Hollow turbine blades are manufactured using complex shaped investment cast cores. 1 SiO 2 and Al 2 O 3 are the most widely used ceramic core materials today. [2][3][4] Especially, Al 2 O 3 ceramic cores have received much attention owing to their excellent high-temperature stability, high-temperature creep resistance, and high-temperature strength.…”

“…Hollow turbine blades are manufactured using complex shaped investment cast cores 1 . SiO 2 and Al 2 O 3 are the most widely used ceramic core materials today 2–4 .…”

A Novel Inorganic Aluminum Phosphate-Based Flame Retardant and Thermal Insulation Coating and Performance Analysis

“…Nano-silica has excellent mechanical strengthening properties and low thermal conductivity, and hollow silica microsphere has better insulation properties. The synergy between them satisfies the optimization of particle size distribution, as the mechanical properties of the coating and the heat transfer mechanism of the coating structure can be improved by adjusting the proportions [ 32 , 33 ]. In addition, they are often used as reaction sources for ceramic or glass phases at elevated temperatures.…”