Research On Performance Testing Technology Of Magnetoelectric Functional Materials And Their Layered Composite Components

As a new type of functional materials,piezoelectric materials and magnetostrictive materials are widely used in non-destructive testing,information storage,refrigeration,photocatalysis,Research and development of transformers,sonar and other devices.And the magnetoelectric composite material composed of the two has application prospects in many fields such as sensors,microwave devices,and memory because it has the coupling characteristics of piezoelectric and magnetostrictive materials at the same time.As a special functional material with mechanical,electrical and magnetic properties at the same time,magnetoelectric functional materials should not only pay attention to their mechanical properties,but also fully clarify their physical properties such as piezoelectric,dielectric,piezoelectric,magneto-elastic,and magneto-electric.Therefore,comprehensively obtaining the piezoelectric coefficient,piezomagnetic coefficient,elastic coefficient,electric hysteresis loop,magnetic hysteresis loop and other material performance parameters of magnetoelectric functional materials under multi-field coupling is of great importance for the application and research of magnetoelectric functional materials.significance.This paper mainly starts from the performance testing technology of magnetoelectric functional materials,and specifically studies the following contents:(1)Comprehensive performance test of piezoelectric materialsFor the typical piezoelectric materials lead zirconate titanate(PZT)and sodium bismuth titanate(BNT),the hysteresis loop,butterfly curve and other key performance parameters of the two are tested by the self-built piezoelectric material comprehensive performance test device.Carry out detailed testing and research work.The results show that the saturation electric field of BNT is about twice that of PZT,and the saturation electric polarization of both is about 0.34C/m~2.The elastic coefficient matrices of PZT and BNT were measured using an ultrasonic resonance test device,and the elastic coefficients of the two were relatively close.The piezoelectric coefficient and relative permittivity of PZT and BNT were measured with a d₃₃ measuring instrument,a self-made d₁₅ fixture and a dielectric thermometer.(2)Comprehensive performance test of magnetostrictive materialsFor the representative magnetostrictive materials FeGa alloy and Terfenol-D,the piezomagnetic coefficient and relative magnetic permeability of FeGa alloy and Terfenol-D were measured by using the self-built magnetic material comprehensive performance test device and ultrasonic resonance test platform.With the change of the bias magnetic field,the maximum value of the piezomagnetic coefficient of FeGa alloy is 19 nm/A,and the maximum value of the piezomagnetic coefficient of Terfenol-D is as high as 26 nm/A.In addition,the hysteresis loop and magnetostriction curve of the two were obtained through the experimental device,and the saturation magnetostriction coefficient of Terfenol-D was nearly four times that of FeGa alloy.Based on the above performance parameters of magnetostrictive materials,the degenerate Zheng-Liu constitutive model is used to nonlinearly fit the experimental data,and the nonlinear phenomenological constitutive equations of typical magnetostrictive materials in a multi-field coupling environment are obtained.(3)Performance test and finite element analysis of layered magnetoelectric composite cantilever beam elementsFeGa/PZT?Terfenol-D/PZT layered magnetoelectric cantilever beam elements were prepared,and the relationship between the magnetoelectric voltage coefficient?_ME and the bias magnetic field Hdc was obtained through the test device.Based on the piezoelectric and magnetostrictive constitutive equations and the boundary conditions of mechanics and electricity,the finite element calculation model of the cantilever beam of the layered magnetoelectric composite element is established.Variation of?_ME with bias magnetic field.The accuracy of the model is verified by comparison with the experimentally measured?_ME.