The Process And Mechainsm Of Magnesium Titanate Ceramic /YIG Ferrites Bonded By Bismuth Glass Solder

Bismuth glass solder were used to connect magnesium titanate ceramics and YIG ferrite ceramics.The connection temperature and holding time were changed,and the interface reaction mechanism of bismuth glass brazing filler was analyzed.On this basis,the bonding experiment between magnesium titanate ceramics and YIG ferrite heterologous ceramics was carried out.The joining process and mechanism of bismuth titanate glass solder joining magnesium titanate ceramic /YIG ferrite were analyzed.The shear strength of joints between magnesium titanate ceramics and YIG ferrite was tested,and the influence of interfacial reaction products on the shear strength of joints was analyzed.By comparing the shear strength of two kinds of glass brazing filler materials,the composition of bismuth glass brazing filler metal,which can form high strength joint between magnesium titanate ceramics and YIG ferrite ceramics,is obtained.The higher the content of B₂O₃ and SiO₂ in bismuth solder,the higher the glass transition temperature and softening point.The slower the viscosity on the surface and YIG ferrite surface is,the higher the temperature needed to achieve good wetting.In wetting test,the wetting angle of bismuth salt glass brazing alloy with B₂O₃ and SiO₂ content is less than 10 degrees below 660 degrees,while the wetting angle of bismuth salt glass brazing filler with high B₂O₃ and SiO₂ content reaches 731 degrees below 10 degrees.Bismuth glass solder connection in temperature on the wetting surface of magnesium titanate ceramics and YIG ferrite,dissolution chemical bonding surface of the ceramic base material,then magnesium titanate ceramics,O-Ti ionic bond failure of bismuth glass solder dissolved ceramic surface process,Ti⁴⁺ was dissolved into the glass solder and ZnO and Bi₂O₃ reaction,formation of interfacial reaction products of bismuth titanate and Zn₂TiO₄ phase,which has Bi₁2 TiO₁2 bismuth titanate and Bi₂Ti₂O₇ two kinds of structure,loss of magnesium titanate into Mg O Ti⁴⁺.The chemical bond bismuth glass solder also dissolved YIG ferrite and YIG ferrite surface damage of O-Y ionic bond and ionic bond O-Fe,Y⁴⁺ and Fe³⁺ was dissolved into the glass solder with Zn O and Bi₂O₃ reaction,generate BiYO₃,ZnFe₂O₄ and Y₂O₃,in addition,YIG ferrite lost Fe³⁺and Y⁴⁺ for Fe₂O₃.The composition design of bismuth glass solder can adjust the coefficient of linear expansion,when the bismuth glass solder line between expansion coefficient between magnesium titanate ceramics and YIG ferrite,can form a joint without crack,expansion coefficient is higher than two parent materials when bismuth glass solder wire,easy to connection joint crack,reduce the shear strength of magnesium titanate ceramics /YIG ferrite joint shear strength can reach 50 MPa without crack,the shear strength of magnesium titanate ceramics /YIG ferrite joint with crack is only about 10 MPa.