磁性微晶玻璃连接铁氧体接头微观组织及力学性能

Microstructure and Properties of Yttrium Iron Garnet Ferrite Ferrite Joint Fabricated by Magnetic Microcrystalline Glass

为得到兼具结构可靠性和电磁功能匹配性的多晶钇铁石榴石型铁氧体(YIG)接头,设计并制备了铋硼镍铁四元玻璃钎料进行YIG铁氧体连接实验,分析了玻璃在铁氧体表面润湿性、接头典型组织、连接温度对接头微观组织及力学性能的影响。结果表明:玻璃钎料在YIG铁氧体表面润湿性良好;制备过程中融入玻璃钎料的Al^(3+)部分取代NiFe_(2)O_(4)和YFe_(3)B_(4)O_(12)中的Fe^(3+),由于Al^(3+)半径更小,晶格畸变更小,使得NiFe_(2)O_(4)和YFe_(3)B_(4)O_(12)的聚集生长得到促进;伴随温度升高,焊缝内细小的NiFe_(2)O_(4)颗粒向大尺寸块状组织转变,证明了高温可以促进NiFe_(2)O_(4)的聚集长大;YIG/玻璃/YIG接头具有较高的剪切强度,在750℃时达到最高强度71 MPa,此后随温度升高接头剪切强度下降,800℃时降至47 MPa。

In order to obtain a polycrystalline yttrium iron garnet ferrite(YIG)joint with both structural reliability and electromagnetic function matching,a new Bi_(2)O_(3)-B_(2)O_(3)-NiO-Fe_(2)O_(3)glass is designed to fabricate YIG ferrite.The wettability of the glass on the surface of YIG ferrite,typical organization,the impacts of brazing temperature to the microstructure of the joint and mechanical properties is investigated.The result shows that the glass have a well wettability on YIG joint.Some Al was incorporated into the glass solution during melting process and replaced Fe^(3+)in NiFe_(2)O_(4)and YFe_(3)B_(4)O12.The growth of NiFe_(2)O_(4)and YFe_(3)B_(4)O_(12)is promoted due to the smaller radius of Al^(3+)and smaller lattice distortion.Small NiFe_(2)O_(4)particles in the seam transform to large blocky organization as the temperature goes up,proving that high temperature has a positive effect on NiFe_(2)O_(4)aggregation.The glass-YIG joint has a high shear strength and reaches its maximum of 71 MPa at 750℃,then the shear strength decreases with increasing temperature,dropping to 47 MPa at 800℃.