Temperature characterization of magnetic and elastic parameters of TFD giant magnetostrictive materials

Abstract

The magnetic and elastic parameters of the Terbium Dysprosium Iron (abbreviated as TFD)giant magnetostrictive material are important fundamental parameters for the design of magnetostrictive transducer based on the piezomagnetic analogy method. Therefore, the study of temperature characteristics of magnetic and elastic parameters of giant magnetostrictive material can help to grasp the law of temperature influence on the working performance of the giant magnetostrictive transducer. In this paper, the variation patterns of magnetic and elastic parameters with temperature for a total of three tangential types of giant magnetostrictive material samples, including the sample along the magnetostrictive direction(TFD-1#), the sample perpendicular to the magnetostrictive direction(TFD-3#) and the sample at an angle of 45° to the magnetostrictive direction(TFD-2#), were comprehensively measured under different external magnetic field conditions. The experimental results showed that: The magnetostriction coefficient is linearly related to the external magnetic field in the range of 10 MPa pre-stress and 50∼150 kA/m external magnetic field (the same below), corresponding to the dynamic operating range of the magnetostrictive transducer. In this interval, the magnetostrictive strain constants d31 and d33 show a single-peak pattern of increasing and then decreasing with increasing external magnetic field, it changes slowly and modestly with increasingly temperature; The relative permeability of the giant magnetostrictive materials μr11 and μr33 decreases with increasing external magnetic field and temperature at an external magnetic field below 150 kA/m; The elastic constant increases with increasing external magnetic field and decreases with increasing temperature.