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

Wen Zheng,Shuai-Bin Hua,Kang-Bo Yu,Chun-Lei Liu,Jing-Xian Zhang,Jie Zhang,Jia-Min Wu,Shuang Chen,Chang-Shun Wang,Yu-Sheng Shi

doi:10.1007/s40145-021-0513-y

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.

Highlights

Silica-based ceramic cores with excellent thermal stabilityJ Adv Ceram 2021, 10(5): 0–0 which will limit the application and development of silica ceramic cores [6,7,8]
The cristobalite peaks located at about 21.80° are detected in all-ceramic samples that contain Al2O3 (0.5, 1.0, 1.5, and 2.0 vol%), and the intensity increases with the increase of Al2O3 content, indicating that Al2O3 can contribute to the formation of cristobalite and its relative content is correlated positively with the Al2O3 content
The silica-based green bodies were fabricated via stereolithography, and the influence of Al2O3 content on mechanical properties and microstructures of the as-sintered silica-based ceramics was systematically investigated

Summary

Introduction

Silica-based ceramic cores with excellent thermal stabilityJ Adv Ceram 2021, 10(5): 0–0 which will limit the application and development of silica ceramic cores [6,7,8]. Li et al [18] investigated the effects of sintering temperatures on the mechanical properties of 3D-printed silica ceramic cores based on stereolithography. Kotz et al [19] realized the significance of raw materials for preparing high-quality fused silica glass. Cai et al [20] pointed out the influence of solid loading and mixing methods on silica glass fabricated by digital light processing (DLP). Their experimental data showed that the viscosity of slurry could be reduced effectively by the multi-step mixing method compared with the one-step mixing method. Liu et al [21] noticed the efficiency problem of fabricating silica glass by stereolithography, developing a stereolithography system using top–down method and obtaining the glassware with similar properties to fused silica

Methods

Results

Conclusion