Design And Output Characteristic Analysis Of Magnetic Field Sensor Based On Fe-Ga/Piezoelectric Laminated Material

Magnetoelectric laminated materials can realize the efficient transformation between magnetic field and electric field,and have the advantages of excellent mechanical properties,strong environmental adaptability,good economic practicality and so on.Therefore,it is widely used in the manufacturing of magnetic field sensor,current sensor,magnetoelectric frequency multiplier,gyroscope and displacement sensor.This paper starts with the performance analysis of the two important components of the magnetic field sensor(magnetostrictive phase and piezoelectric phase),and analyzes the output characteristics of the magnetic field sensor and the factors influencing its output characteristics from three aspects of theoretical derivation,finite element simulation analysis and experimental research.Based on the nonlinear constitutive model of the magnetostrictive material,the dynamic expressions of the core parameters such as strain,Young’s modulus,magnetostrictive coefficient and relative permeability of the magnetostrictive phase are derived,and then the performance parameters of the piezoelectric material are analyzed.Finally,the equivalent circuit model of the magnetic field sensor is optimized.To build the test platform of the magnetic properties of magnetostrictive materials,respectively tested three kinds of typical magnetostrictive materials(Terfenol-D,Fe-Ga,Fe-Co-V)of the magnetic properties,selection of Fe-Ga as a measurement in low magnetic field,magnetic field sensor piezomagnetic materials,and the dynamic of Fe-Ga material magnetostrictive coefficient,smooth coefficient,mechanical coupling coefficient and hysteresis characteristics parameters for the experimental study.The three-dimensional finite element model of Fe-Ga/PZT-5H magnetic field sensor was established,and the magnitude and distribution of the internal magnetic field,stress and electric field were analyzed when the magnetic field sensor was working.The force distribution,magnetic field distribution and induced voltage distribution of the magnetic field sensor in asymmetric mode and symmetric mode are analyzed.The effects of different piezoelectric materials,two-phase ratio,length-width ratio and prestress on the output characteristics of magnetic field sensors are analyzed.The prototype of L-T Fe-Ga/PZT-5H/Fe-Ga magnetic field sensor was designed and manufactured.A testing platform for magnetoelectric characteristics of magnetic field sensors was built.The output characteristics of the magnetoelectric laminated magnetic field sensor are tested.The effects of bias magnetic field,volume ratio of piezo and piezo phase on the magnetoelectric coefficient are analyzed.