Microstructure and characterization of interfacial phases of sapphire/sapphire joint bonded using Bi2O3-B2O3-ZnO glass

摘要

Bismuth borate zinc glass, 50Bi(2)O(3)-30B(2)O(3)-20ZnO (mol.%), was used as a braze intended to join sapphire. Thermal properties of the glass were all experimentally determined. The wettability of the glass on sapphire was investigated. The contact angle not greater than 11.3 degrees was obtained in air at temperatures of >= 700 degrees C Subsequently, sapphire was successfully joined to themselves at 700 degrees C for 20 min. The microstructure of the joint was studied and the interfacial phases were characterized. The results showed that the ZnAl2O4 phase was formed as a result of the reaction between the sapphire substrate and ZnO from the glass. The mechanical integrity of the joints was investigated. The joints with an average room shear strength of 70 MPa were achieved. The fracture analysis indicated that the fracture occurred within the glass interlayer rather than at the sapphire/glass interface, hence indicating a good bonding of the glass with sapphire. (C) 2016 Elsevier Ltd. All rights reserved.