Salach Jacek, Kachniarz Maciej, Jackiewicz Dorota, Bieńkowski Adam
Institute of Metrology and Biomedical Engineering, Warsaw University of Technology, A. Boboli 8, 02-525 Warsaw, Poland.
Materials (Basel). 2024 Dec 20;17(24):6239. doi: 10.3390/ma17246239.
The magnetoelastic effect is known as the dependence between the magnetic properties of the material and applied mechanical stress. The stress might not be applied directly but rather generated by the applied torque. This creates the possibility of developing a torque-sensing device based on the magnetoelastic effect. In this paper, the concept of an axially twisted toroidal magnetic core as a torque-sensing element is considered. Most known works in this field consider the utilization of an amorphous ribbon as the core material. However, Ni-Zn ferrites, exhibiting relatively high magnetostriction, also seem to be promising materials for magnetoelastic torque sensors. This paper introduces a theoretical description of the magnetoelastic effect under torque operation on the basis of total free energy analysis. The methodology of torque application to the toroidal core, utilized previously for coiled cores of amorphous ribbons, was successfully adapted for the bulk ferrite core. For the first time, the influence of torque on the magnetic properties of Ni-Zn ferrite was investigated in a wide range of magnetizing fields. The obtained magnetoelastic characteristics allowed the specification of the magnetoelastic torque sensitivity of the material and the determination of the optimal amplitude of the magnetizing field to maximize this parameter. High sensitivity, in comparison with previously studied amorphous alloys, and monotonic magnetoelastic characteristics indicate that the investigated Ni-Zn ferrite can be utilized in magnetoelastic torque sensors. As such, it can be used in torque-sensing applications required in mechanical engineering or civil engineering, like the evaluation of structural elements exposed to torsion.
磁弹性效应是指材料的磁性与外加机械应力之间的依赖关系。应力可能不是直接施加的，而是由外加扭矩产生的。这为开发基于磁弹性效应的扭矩传感装置创造了可能性。本文考虑了将轴向扭曲的环形磁芯作为扭矩传感元件的概念。该领域中大多数已知的研究都考虑使用非晶带作为磁芯材料。然而，具有相对较高磁致伸缩的镍锌铁氧体似乎也是磁弹性扭矩传感器的有前途的材料。本文基于总自由能分析，对扭矩作用下的磁弹性效应进行了理论描述。先前用于非晶带绕线磁芯的向环形磁芯施加扭矩的方法，成功地应用于块状铁氧体磁芯。首次在很宽的磁化场范围内研究了扭矩对镍锌铁氧体磁性的影响。所获得的磁弹性特性使得能够确定材料的磁弹性扭矩灵敏度，并确定使该参数最大化的最佳磁化场幅度。与先前研究的非晶合金相比，高灵敏度和单调的磁弹性特性表明，所研究的镍锌铁氧体可用于磁弹性扭矩传感器。因此，它可用于机械工程或土木工程中所需的扭矩传感应用，如对承受扭转的结构元件的评估。
