Properties of Li-Ti Ferrite/magnesium Titanate Ceramic Joint Bonded by Bi₂O₃-ZnO-SiO₂-B₂O₃ Glass Braze

Bi₂O₃-ZnO-SiO₂-B₂O₃ glass braze was used for the joining of Li-Ti ferrite and magnesium titanate ceramic. The phase compositions of Li-Ti ferrite and magnesium titanate ceramic substrates, glass braze and interface domains were characterized by X-ray diffraction. The microstructure and elemental distribution within the brazed joints were analyzed by field emission scanning electron microscopy and energy dispersive X-ray spectroscopy, respectively. The shear strength of joints was also evaluated. The results show that the bonding of Li-Ti ferrite and magnesium titanate ceramic by using Bi₂O₃-ZnO-SiO₂-B₂O₃ glass braze is effective at an appropriate bonding temperature. The joints are nearly free of defects, such as voids and cracks. The interface reaction between glass braze and magnesium titanate ceramic can form a white rod Bi₄Ti₃O₁₂ phase and rich magnesium ceramic particles. The suitable interface reaction can favor obtaining a higher connection strength, and the maximum of shear strength is 35 MPa at 700℃.