Giant Stress-Impedance Effect in CoFeNiMoBSi Alloy in Variation of Applied Magnetic Field.

Piotr Gazda,Michał Nowicki

doi:10.3390/ma14081919

Abstract

The article presents the stress impedance investigation of CoFeNiMoBSi alloy in variation of the applied magnetic field. In order to carry out the study, a specialized stand was developed that allows for loading the sample with stresses and simultaneous action of the DC (direct current) magnetizing field. The tests were carried out for as-cast and Joule annealed samples. The significant influence of the magnetizing field acting on the sample on the stress-impedance results was demonstrated and the dependence of the maximum impedance change in the stress-impedance effect was determined, depending on the field acting. The obtained results are important due to the potential use of the stress-impedance effect for the construction of stress sensors.

Highlights

Since the discovery of the stress-impedance (SI) effect in amorphous alloys by Shen et al [1], there has been ongoing research in both understanding and maximizing this effect from a material science point of view [2,3,4,5,6,7,8,9], and sensor development for practical engineering applications [10,11,12,13,14]
The most known of the magnetomechanical effects are magnetostrictive and Villari effects [33], the latter leads to a change in magnetic permeability due to the mechanical stress, by inducing temporary magnetic anisotropy in stress direction [34]
The model that best describes this phenomenon was presented by Sablik et al [47]. This solution uses the concept of the effective magnetic field Heff, acting on the sample, taking into account the variable and constant components of the acting magnetic field, mechanical stress, and others

Summary

Introduction

Since the discovery of the stress-impedance (SI) effect in amorphous alloys by Shen et al [1], there has been ongoing research in both understanding and maximizing this effect from a material science point of view [2,3,4,5,6,7,8,9], and sensor development for practical engineering applications [10,11,12,13,14]. With positive and negative magnetostriction, exhibit a significant Villari effect, which alters the material’s magnetic permeability [15,16,17,18,19,20]. Due to the changes of magnetic permeability, the skin depth of the high-frequency current changes, which leads to significant changes in the material’s impedance [21]. This effect constitutes the base of the SI phenomena. The most known of the magnetomechanical effects are magnetostrictive and Villari effects [33], the latter leads to a change in magnetic permeability due to the mechanical stress, by inducing temporary magnetic anisotropy in stress direction [34]

Methods

Discussion

Conclusion