Magnetic after-effect study of dislocation relaxation in Fe-based alloys

Abstract

To cite this version:B Minov, L Dupré, M J Konstantinović. Magnetic after-effect study of dislocation relaxation in Fe-based alloys. Journal of Physics D: Applied Physics, IOP Publishing, 2011, 44 (30) Abstract. Dislocation-related relaxation processes are studied by measuring the magnetic after-effect spectra as a function of temperature in a variety of non-deformed and cold-worked iron alloys. In the α-Fe and Fe-1%Cu alloys the peak centered at about 320 K appears as a consequence of plastic deformation. On the basis of the behavior of its parameters, such as the temperature position of the peak, the full width at half maximum, and the integrated intensities, this feature is assigned to the relaxation process of thermally-activated dislocation motion.

The study of dislocation dynamics in thermally aged Fe–1%Cu–C alloys by internal friction measurements

“…This peak has been already observed and analysed by magnetic after-effect and IF spectra of α-Fe and Fe-Cu alloys, and assigned to the relaxation process of thermally activated dislocation motion (CWD-peak). As already discussed [19], the activation energy of the CWD-peak (1.1 eV) is somewhat different from the γ -relaxation (1.07 eV) [20,24,25], which is typically observed in pure metals. These facts as well as its overall shape indicate that E 2 peak could be equivalent to the double kink- pair relaxation process, which occurs in alloys.…”

“…This peak is associated with the joint motion of dislocations and carbon atoms [18]. Recently, another peak which appears at lower temperatures (320 K) has been assigned to thermally activated dislocation motion (CWD-peak) [19]. The activation energy of this peak is determined to be of about 1.1 eV, on the basis of the magnetic after-effect and IF spectra.…”

Experimental Determination of the Preisach Model for Grain Oriented Steel

“…Existing thermal effects can slowly change magnetic momentum of the magnetic domain. Also a small change of the flux density for a constant magnetic field strength is reported and it is known as the after-effect [7,8]. Unfortunately, it is a very difficult task to find whether the complication is of experimental nature or a material feature, or both of them with different contribution.…”

Difficulties Caused by Magnetic After-effect during Identification of the Preisach Hysteresis Model Weighting Function

“…Magnetically hard materials are usually measured using a vibrating magnetometer while the time response of the magnetization is generated from a jump of the field strength most often to the coercive force value H c [2,6]. Other approach is to measure time dependence of the inductance or susceptibility using a small signal after the bulk field strength change [1,7]. Other authors analyze dynamics hysteresis loops and determine the ratio of the eddy current and the after-effect [8].…”