Papers by Keyword: Thermomagnetic Treatment

Abstract: The paper describes the influence of thermomagnetic treatment on the parameters of the amplitude dependence of internal friction, the crystal and magneto-crystalline structure of Fe alloys with ferrite structure: Fe – 8%Cr, Fe – 16%Cr, Fe – 19%Cr, Fe – 4%Cr – 2%V, Fe – 3%Cr – 3%Al, and Fe–1.2%C–2% Si–2%Al graphitic steel with graphite and ferrite structure. The thermomagnetic treatment was carried out at a temperature of 450ºС. The structure was studied by means of metallography, X-ray crystal structure analysis, ferromagnetic resonance, and nuclear gamma resonance spectroscopy. It is shown that, the larger the ferrite grain in alloys with ferrite structure is, the greater an increase in internal friction is, in the amplitude range up to approximately the amplitude of its maximum owing to thermomagnetic treatment. The change of the damping properties of graphitic steel caused by thermomagnetic treatment is relatively small, due to a large number of diamagnetic inclusions of graphite and quite fine-grained ferrite matrix. The results of the X-ray crystal structure analysis, the ferromagnetic resonance and nuclear gamma resonance spectroscopy have shown that, in the case of thermomagnetic treatment, diffusion redistribution of atoms of alloying elements, combined with the change of structural anisotropy, takes place in Fe-Cr alloys.

Abstract: The authors studied the effect of the pre–heat treatment and subsequent thermomagnetic treatment on the damping and magnetic properties of the Fe–Cr–Al alloy system. This article reveals the dependences of influence of chromium and aluminum on the thermomagnetic treatment effect. As a result, the study identified the optimal modes of treatment of the alloys to maximize the damping capacity.

Abstract: A new way of considerable improvement of properties of soft magnetic alloys is offered. This way actually consists in the use of an ion beam treatment in the manufacturing technology for these alloys. Depending on the properties, which need improvement (magnetic softness or magnetostriction), the ion beam treatment is performed before or after a thermomagnetic treatment.

Abstract: The paper deals with the domain structure and electromagnetic characteristics of soft magnetic iron-based alloys, which are formed by the impact of thermomagnetic treatment (TMT) - cooling of the material in the presence of a magnetic field. The effect of reducing the specific magnetic loss in materials, using a constant or alternating (different frequency) magnetic field is determined. It is shown that the minimum magnetic losses in the materials are obtained after TMT in an alternating magnetic field at high (~ 80 kHz) frequencies. This shows up the perspectives of TMT of soft magnets.

Abstract: A new concept is suggested that serves to explain the effects of thermomagnetic treatment. Its validity is proved via measurements of magnetic properties and electron microscopy examination of structure of soft magnetic materials after different treatments. This concept allows one to consciously choose the treatment mode aiming on improvement of magnetic properties of alloys.