Comparison of magnetoelastic properties between the 〈110〉 oriented TbxDy1-xFe1.95 polycrystalline alloys with different Tb/Dy composition ratio under magnetomechanical loading

This paper presents comparison of magnetoelastic properties between the 〈110〉 oriented Tb x Dy 1-x Fe 1.95 polycrystalline alloys for x = 0.27, 0.3, 0.45 under coupled loading of magnetic field and compressive stress. The simultaneously measure are investigated for the magnetization and magnetostriction under applied magnetic field from -200 to 200 kA/m and compressive stress from 0 to 50 MPa along the rod axis at room temperature. The results show that, according to the increase of Tb concentration and compressive stress, the hysteresis, coercive force and magnetostriction hysteresis loops of Tb x Dy 1-x Fe 1.95 alloys increase rapidly and the distortion of the hysteresis loops occurs at higher compressive stress, especially Tb 0.45 Dy 0.55 Fe 1.95 alloys, while the maximum relative permeability of Tb x Dy 1-x Fe 1.95 alloys monotonously decrease. Meanwhile, the higher the Tb concentration the stronger is magnetostrictive "jump" effect. For these experimental results, the effect of compressive stress and Tb / Dy ratio on magnetoelastic properties of Tb x Dy 1-x Fe 1.95 alloys are coupling and remarkable. A tradeoff and optimization are very important for many engineering designs and applications.

MAGNETOELASTIC PROPERTIES DEPENDENCE ON COMPRESSIVE STRESS IN 〈110〉 ORIENTED Tb0.45Dy0.55Fe1.95 POLYCRYSTALLINE ALLOYS WITH HIGH DRIVE LEVELS

This paper presents the magnetoelastic properties for the relative high Tb / Dy composition ratio 〈110〉 oriented Tb 0.45 Dy 0.55 Fe 1.95 polycrystalline alloys. The simultaneous measurements of the magnetization and magnetostriction are carried out as a function of applied magnetic field range of 0 to 800 kA/m and compressive stress from 0 to 60 MPa. The maximum piezomagnetic coefficient $(d^{\rm max}_{33})$ and magnetostriction hysteresis (Wh) are obtained by differential calculation from the experimental curves. According to the increase of compressive stress, an obvious magnetostriction "jump" effect is observed, and the magnetostriction with the magnetic field of 800 kA/m (λ800) and magnetostriction hysteresis monotonously increase, while the maximum piezomagnetic coefficient increases first from 0 to 10 MPa and then decreases from 10 to 60 MPa. Here, results of measuring and calculating on this material are important complement to further understand the rules of the magnetoelastic properties in high Tb/Dy composition ratio Tb 0.45 Dy 0.55 Fe 1.95 polycrystalline alloys for theoretical approaches and modern technology applications.