Microstructure and mechanical properties of SiO2-BN ceramic and Invar alloy joints brazed with Ag-Cu-Ti + TiH2 + BN composite filler

H-BN particles modified composite filler was prepared to braze SiO2-BN ceramic and Invar alloy. The maximum shear strength of the joints brazed with the composite filler reached 39 MPa, which was 30% greater than that brazed with single Ag-Cu-Ti alloy. The improvement of the joint strength was attributed to the variation of joint microstructure and the reduction of tensile stresses induced in the SiO2-BN ceramic.364