Joining SiO₂ based ceramics: recent progress and perspectives

Nowadays, SiO₂ based material is one of the widest used materials in optical, microelectromechanical system, aerospace and some other industries. In practical application, SiO₂ based materials are required to be joined with themselves or other heterogeneous materials to assemble products with various functions. And the joining quality directly affects the mechanical performances and functional properties of assembled products. Though many researchers studied different joining technologies, explored the microstructure of joining interface and tested after-joining properties, a review that summarizes the recent cutting-edge researches and development tendency of joining technologies for SiO₂ based ceramics is still absent. Therefore, according to different applications and requirements, this review summarizes the widely used joining technologies and discusses corresponding joining mechanisms, current research progress and suitable applications. Due to the wide applications in specific industry, laser welding, anodic bonding and wafer bonding are discussed in detail. Further, brazing, the widest used method in SiO₂ joining, has been elaborated deeply in its wetting mechanism, residual stress control, interfacial microstructure and mechanical performance aspects. In the end, this review proposed the future development trends of SiO₂ ceramics joining, aiming at offering a full-view of potential improvements in SiO₂ ceramic joining technologies.