The internal stresses dependence of the magnetic properties of cast amorphous microwires covered with glass insulation

Magneto-elastic anisotropy of ferromagnetic glass-coated microwires

“…For each microwire, the internal stress is computed from the metallic core diameter and the glass thickness through the model proposed in Ref. [5]. We took the following data for the thermal expansion coefficient of glass and metal: 3.2 Â 10 À6 and 1.2 Â 10 À5 K À1 , and for the Young's moduli: 64 and 110 GPa, respectively.…”

Effect of the metal-to-wire ratio on the high-frequency magnetoimpedance of glass-coated CoFeBSi amorphous microwires

“…Torcunov [14] modeled the thermoelastic and quenching stresses that occur in glass-coated wires and evaluated with a thermodynamic model the stress components in terms of their axial σ zz , radial σ rr and azimuthal σ φφ components (in a cylindrical system of coordinates (r, φ, z) with the z direction along the wire axis). The following expressions (providing the Poisson's coefficients of the glass and metal are equivalent ν g ∼ ν m ∼ 1/3 ) are obtained and adapted to our case:…”

“…Glass-coated amorphous microwires of nominal composition Co 69.4 Fe 3.7 B 15.9 Si 11 were prepared by fast cooling with the Taylor-Ulitovski technique 14 . Several metal-to-wire ratio values, p = φ m /φ w , with φ m the metallic core diameter and φ w the total wire diameter, were produced and characterized.…”

Influence of glass coating thickness and metallic core diameter on GMI effect of glass-coated Co68Fe4.5Si13.5B14 amorphous microwires

“…Larin et al [14] indicated that the internal stress mainly consisted of quenching stress owing to the difference in temperatures of glass and metallic core as well as thermoelastic stress resulting from the difference in the expansion coefficients of glass and metallic core. The order of the thermoelastic stress was GPa, and the quenching stress was small enough to be neglected when the internal stress of the microwire was taken into account.…”

“…The stress calculation formula provided by Larin [14] indicated that for the metallic core with constant diameter, both the radial compression stress and circumferential stress of the microwire increased with the glass coating thickness, and the stress increments were decreased gradually. Such increases of the radial stress and circumferential stress led to the increase both in the stress anisotropy energy [15], which enhanced GMI effect of microwire.…”