P. Pietrusiewicz

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.

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.

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.

The surface structural and mechanical properties of the amorphous CO22Y54AL24 ribbon

The aim of this study was to manufacture amorphous Co22Y54Al24 alloy in a form of thin ribbons and to investigate their properties. The investigated ribbons were prepared by rapid solidification of molten metal on a rotating copper cylinder (melt-spinning). In order to obtain the material with amorphous structure, the cooling rate of the liquid alloy should vary in a range from 104 to 106 K/s. The microstructure studies were performed using X-ray diffractometery. The mechanical properties were investigated by metallographic studies, micro-hardness and tribological resistance tests moreover the surface roughness profile were analyzed. All studies were performed for two sides of tapes, since the differences in ribbons surface, related with manufacturing process, are clearly visible. The surface from the bottom (drum side) was glossy and from the top side it was shiny.