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Structural and Mossbauer spectroscopy studies of metallic powders Fe-Al and Fe-Al-X (X = Ni, Cu, O obtained by the self-decomposition method

Hanc A., Frąckowiak J. E., Binczyk F.

Inżynieria Materiałowa

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2007

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Vol. 28, nr 3-4

166-168

EN

In the present work the Fe-Al-X (X=Cu;Ni;Cr) metallic powders produced by the self-decomposition method of the Fe-Al doped alloys were examined by Mossbauer spectroscopy. The concentration of the Fe vacancies and the Fe atoms substituting Al (Fe-AS) was determined from the intensities of the sub-spectra in the Mossbauer analysis connected with distinct Fe environments. The results show that nickel and copper cause the increase of vacancy concentrations in comparison with values found for Fe-Al metallic powders, whereas chromium decreases vacancy concentrations causing a significant increase of anti-site atoms Fe-AS concentration.

PL

W pracy przedstawiono mossbauerowskie oraz struktualne badania faz międzymetalicznych występujących w proszkach metalicznych Fe-Al oraz Fe-Al-X (X=Cu;Ni;Cr) otrzymanych metodąl samorzutnego rozpadu. Metodą spektroskopii efektu Móssbauera wyznaczono koncentracje defektów punktowych tj. wakansje oraz atomy antypołożeniowe Fe-AS. Na podstawie otrzymanych wyników stwierdzono, iż badane proszki metaliczne zawierają wyższą koncentracje defektów punktowych w porównaniu do materiałów otrzymywanych metodami konwencjonalnymi Wykazano, że zastosowanie jako domieszek atomów niklu oraz miedzi prowadzi do podwyższenia koncentracji wakansów w porównaniu do koncentracji wyznaczonych dla faz Fe-Al. Natomiast domieszki chromu powodują obniżenie koncentracji wakansów powodując jednocześnie wzrost koncentracji atomów zajmując pozycje antypołożeniowe.

2

Structure and magnetic properties of powder HITPERM material

Konieczny J., Dobrzański L. A., Frąckowiak J. E.

Archives of Materials Science and Engineering

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2007

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Vol. 28, nr 3

156-164

EN

Purpose: The aim of the work is to investigate the structure and magnetic properties of the cobalt based HITPERM amorphous alloy Co68Fe4Mo1Si13.5B13.5 subjected high-energy ball milling and to the isothermal annealing to a combination of these two technologies. Design/methodology/approach: The nanocrystalline ferromagnetic powders were manufactured by highenergy ball milling of metallic glasses ribbons in as state. Using the HFQS program the distributions of the magnetic hyperfine P(H) fields were determined for spectra smoothed in this way, employing the Hesse-Rübartsch method. Observations of the structure of powders were made on the OPTON DSM-940 scanning electron microscope. The diffraction examinations and examinations of thin foils were made on the JEOL JEM 200CX transmission electron microscope equipped in equipped with the EDS LINK ISIS X- ray energy dispersive spectrometer made by Oxford. Graphical analyses of the obtained X-ray diffraction patterns, as well as of the HC=f(TA) relationship were made using the MICROCAL ORIGIN 6.0 program. Findings: The analysis of the structure and magnetic properties test results of the HITPERM powders alloy Co68Fe4Mo1Si13.5B13.5 obtained in the high-energy ball of milling process proved that the process causes significant decrease in the magnetic properties. The magnetic properties of this material and structure and may be improved by means of a proper choice of parameters of this process as well as the final thermal treatment. Research limitations/implications: For the soft magnetic powder material, further magnetical, composition examinations and structure are planed. Practical implications: Feature an alternative to solid alloys are the amorphous and nanocrystalline metal powders obtained by milling of metallic glasses and make it possible to obtain the ferromagnetic nanocomposites, whose dimensions and shape can be freely formed. Originality/value: The paper presents results of influence of parameters of the high-energy ball milling process on magnetic properties and structure of soft magnetic powder HITPERM alloy obtained in this technique. The paper compares magnetic properties and structure of the HITPERM alloy obtained in high-energy ball milling process, melt spinning technique and in a combination of these two technologies.

3

Structure and properties of the powder obtained from the amorphous ribbon

Konieczny J., Dobrzański L. A., Frąckowiak J. E.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 18, nr 1-2

143--146

EN

Purpose: The aim of the work is to investigate the magnetic properties of the cobalt based Co68Fe4Mo 1Si13.5 B13.5 amorphous alloy subjected to the isothermal annealing, high-energy milling and to a combination of these two technologies. Design/methodology/approach: The powder test piece obtained from the input amorphous ribbon in high-energy ball milling. Distributions of the magnetic hyperfine P(H) fields were determined for spectra smoothed in this way, by using the HFQS program, employing the Hesse-Rübartsch method. The diffraction examinations and examinations of thin foils were made on the JEOL JEM 200CX transmission electron microscope. Observations of the structure of powders were made on the Opton DSM-940 scanning electron microscope. Findings: The analysis of the magnetic properties test results of the of the Co68Fe4Mo 1Si13.5B13.5 powders obtained in the high-energy ball of milling process proved that the process causes significant decrease in the magnetic properties. The structure and magnetic properties of this material may be improved by means of a proper choice of parameters of this process as well as the final thermal treatment. Research limitations/implications: For the powders, further magnetical, structure and composition examinations are planed. Practical implications: The amorphous and nanocrystalline metal powders obtained by milling of metallic glasses feature an alternative to solid alloys and make it possible to obtain the ferromagnetic nanocomposites, whose shape and dimensions can be freely formed. Originality/value: The paper presents influence of parameters of the high-energy ball milling process on structure and magnetic properties of soft magnetic powder materials obtained in this technique. The paper compares structure and magnetic properties of the Co 68Fe4Mo 1Si13.5B13.5 alloy obtained in high-energy ball milling process and melt spinning technique.

4

Morphology changes of ultra high molecular weight polyethylene occurring on the surface, in the subsuperficial zone, and in volume as a result of friction in polymer/metal system

Cybo J., Maszybrocka J., Frąckowiak J. E.

Inżynieria Materiałowa

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2004

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R. XXV, nr 3

295-298

EN

The mechanisms and opportunities for considerable reduced wear permanent deformation of the UHMWPE element in a polymer/ metal friction couple have been studied. As a result of initlial plastic deformation and electron beam irradiation of a semi-finished material used for the acetabular cup endoprotheses, a change of the biopolymer internal structure was achieved. It was observed that a proper ratio of high and low molecular fractions of UHMWPE has made possible flat reorientation of lamellas in the friction zone during plastic deformation induced by the tribological process and reduction of the deformed zone thickness and of its wear value. In optimum samples, a reduction of the so-called free volume takes place in the polymer. This is conducive to obtaining a high degree of the structure arrangement and, in consequence, to an improvement of the micromechanical properties (microhardness, modulus of elasticity, and resistance to microwear and to permanent strain) of the entire cross-section of the investigated biopolymer specimens.

PL

Zinterpretowano mechanizmy i możliwości kilkukrotnego ograniczenia zużycia oraz trwałej deformacji polietylenowego elementu w polimerowo-metalowym węźle tarcia. Poprzez wstępne odkształcenie plastyczne i napromieniowanie wiązką elektronów półproduktu panewek endoprotez uzyskano zmianę wewnętrznej budowy biopolimeru. Zapewnienie właściwej proporcji frakcji wysoko- i niskomolekularnej oraz semikrystalicznej postaci UHMWPE stworzyło wariantom predestynowanym do zastosowań tribologicznych możliwość: płaskiej reorientacji lamel w strefie tarcia podczas deformacji plastycznej wywołanej procesem tribologicznym, ograniczenia grubości strefy zdeformowanej i wartości zużycia. W wariantach optymalnych zachodzi równocześnie zmniejszenie tzw. objętości swobodnej (nanopustek) w całej masie polimeru. Sprzyja to uzyskaniu dużego stopnia przestrzennego uporządkowania struktury, a w konsekwencji poprawie właściwości mikromechanicznych (mikrotwardości, modułu sprężystości oraz odporności na mikrozużycie i trwałą deformację) całego przekroju poprzecznego badanych próbek biopolimeru.