Low-Temperature Brazing of Sicp/Al Composites with Bi2o3-B2o3-Zno-Sio2-Al2o3 Glass in Air

Abstract

In this study, low-melting Bi2O3-B2O3-ZnO-SiO2-Al2O3 (BBZSA) glass was adopted to braze SiCp/Al composite, and the effects of brazing temperature and holding time on the microstructure and mechanical properties of the SiCp/Al joint were investigated. The BBZSA glass started to spread and wet on the surface of SiCp/Al composite at the temperature of 480°C. The typical microstructure at this temperature was SiCp/Al +Bi2O3-B2O3-ZnO glass+Bi24B2O39+Si2Al2O7+SiO2, and the interface was bonded by the intermolecular force between the Bi2O3-B2O3-ZnO (BBZ) glass and SiCp/Al composite. Besides, the precipitation of the Bi24B2O39 phase improved the mechanical properties of the joint with a maximum strength of 17.3 MPa, and the fractures all occurred in the Bi2O3-B2O3-ZnO (BBZ) glass of the brazing seam. The proof-of-concept study on the brazing of SiCp/Al composite with BBZSA glass provides insights in the further development of ceramic/metal composite joining.

Keywords: SiCp/Al composite, Bi2O3-B2O3-ZnO-SiO2-Al2O3 glass, brazing, mechanical properties