M. Nabiałek

Influence of Solidification Speed on Quality and Quantity of Structural Defects in Fe61Co10Zr2.5Hf2.5Y2W2B20 Amorphous Alloy

The microstructure of Fe61Co10Zr2,5Hf2,5Nb2W2B20 amorphous alloy in the form of ribbons obtained by classical melt spinning and plates obtained by an induction suction method were investigated using X-ray diffraction. The type of structural defects were studied by analysis of the magnetization characteristics near ferromagnetic saturation of the sample. It was shown that the presence of structural defects is strongly correlated with sample thickness and production process. It was shown that ribbons with cooling rate between 105-106 K/s have point type defects, wires obtained with lower cooling rate between 101-102 K/s, have linear type defect (quasi-dislocation dipoles). crystallization.

Effect of heat treatment on the shape of the hyperfine field induction distributions and magnetic properties of amorphous soft magnetic Fe62Co10Y8B20 alloy

Abstract Thermal treatment, undertaken at just below the crystallization temperature, has led to nanocrystallization and has had a significant impact on the shape of the hyperfine field induction distributions of Fe62Co10Y8B20 alloy and on its soft magnetic properties. In the amorphous ferromagnetic alloys, it is possible to indirectly determine the effect of the structure stresses, resulting from the presence of structural defects, on the soft magnetic properties of these materials. It has been found that a change in the parameters associated with the presence of structural defects affects the shape of the hyperfine field distributions of 57Fe.

The microstructure and magnetic properties of Nd8.5Tb1.5Fe83Zr1B6 ribbons obtained at various cooling rates

Abstract The paper presents results of microstructure and magnetic properties studies of Nd8.5Tb1.5Fe83Zr1B6 ribbons obtained by melt-spinning technique. The samples were produced using the rapid cooling of liquid alloy on the copper wheel, by applying three different linear velocities 20, 30, and 35 m/s. The microstructure of obtained ribbons was examined using X-ray diffractometry and Mössbauer spectroscopy. Magnetic measurements were performed using LakeShore vibrating sample magnetometer. The microstructure measurements were used for quantitative and qualitative analysis of phase composition. Basing on results of structure studies combined with magnetic measurements, the influence of phase composition on hysteresis loop behavior was described.

Analysis of the structure (XRD) and microstructure (TEM, SEM, AFM) of bulk amorphous and nanocrystalline alloys based on FeCoB

Abstract Control of the formation process of amorphous materials, and the lowering of their internal energy as a result of atomic transition through subsequent potential barriers describing metastable states, represent direct factors in designing the functional properties of these modern materials. This paper presents the results of tests carried out on the group of four alloys: Fe62-xCo10Y8MexB20 (where: Me = Cr, Be or Cu; x = 0 or 1), obtained by a suction-casting method. The bulk amorphous samples were obtained in the form of plates of thickness 0.5 mm. The structure and microstructure of the investigated plates, in the as-quenched and after-annealing states, were studied using: scanning and transmission electron microscopy, atomic force microscopy and X-ray diffractometry. Moreover, for heat-treated samples, Rietvelds analysis was performed. Additionally, the combination of microscopy and X-ray studies allowed for the observation of diffusion effects occurring in the material.

An investigation into the effect of isothermal annealing on the structure (XRD), microstructure (SEM, TEM) and magnetic properties of amorphous ribbons and bulk amorphous plates

Abstract Test samples of the alloy Fe61Co10Y8W1B20 were fabricated in the form of both amorphous ribbons and bulk amor-phous plates. The structure, microstructure and magnetic properties of samples in the as-quenched state and after annealing were investigated. The aim of the paper is to show the effect of the thermal treatment on the structural changes occurring in the amorphous state. The thermal treatment, performed at well below the crystallisation temperature, did not cause crystallisation. In the investigated amorphous alloys it has been found that, after a specific thermal treatment, structural relaxation occurs in the presence of structural defects, such as quasidislocational dipoles. Also, supporting the microscopy investigations with measurements of the magnetic properties can be extremely beneficial for facilitating description of the real structure and properties of the amorphous alloys; further, this testing combination offers the possibility for designing the optimal application parameters for an alloy.

Application of computed tomography for an analysis of composite with fine dispersive reinforcement made of the Fe65Co10Ni3W2B20 alloy

Purpose: The paper presents the results of microstructure and mechanical properties of composites resulting from a combination of powders of metallic glasses with an epoxy resin (Epidian 100). The study was performed using computed tomography. Design/methodology/approach: The filler used was made of a Fe65Co10Ni3W2B20 amorphous alloy based on, showing in the state after the formation the soft magnetic properties. The aim of the study was to determine the effect of the fraction of the composite powders on the microstructure parameters (mean pore diameter and pore volume fraction) and the properties of the obtained composites. Findings: Based on the survey it was found out that size fraction used does not affect the value of the modulus of elasticity linear composites studied. It was also shown that the composites analysed in an attempt to compress the cross cracked grain boundaries. The influence fraction powders and change the share of the pore size depending on the fraction of the filler. Research limitations/implications: No studies of the magnetic properties determine the usefulness of these materials in the electronics industry. Practical implications: Practical implications are to size the test specimens in the limited range of tests. In the future, it is planned to produce samples with a larger diameter. Originality/value: The paper presents a new group of composites-based metallic glasses conditions characterised by good properties produced a simple and inexpensive method.