Wyniki wyszukiwania - Biblioteka Nauki

1

Torque pulsation of an inductive engine supplied from a voltage inverter

100%

Frąckowiak J.

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2007

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tom No 56

105-111

EN

The paper presents the simulation results of a torque of a driving engine. An automotive vehicle is driven with a three-phase induction motor supplied from a voltage inverter and accumulator battery. The mathematical model of the vehicle is determined by differential equations of an induction motor, equations of motion of a vehicle, resistance to motion in the form of a trinomial square, voltage inverter of single-sideband regular modulation of impulse width, and accumulator battery.

2

Dynamika pojazdów samochodowych napędzanych silnikiem indukcyjnym i szeregowym prądu stałego

100%

Frąckowiak J.

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2006

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tom Nr 50

97-105

PL

W artykule przedstawiono porównanie parametrów dwóch pojazdów samochodowych: jeden napędzany silnikiem indukcyjnym zasilanym z falownika napięcia i baterii akumulatorów, drugi napędzany silnikiem szeregowym prądu stałego zasilany z baterii akumulatorów poprzez czoper. Model matematyczny pojazdów stanowią równania napięciowo-prądowe odpowiednich silników, równanie ruchu pojazdu, opory ruchu w postaci trójmianu kwadratowego, falownik napięcia o jednobiegunowej regularnej modulacji szerokości impulsów, czoper oraz bateria akumulatorów. Uwzględniono straty rnocy: w uzwojeniach silników, w obwodzie magnetycznym, mechaniczne oraz straty w falowniku i czoperze.

3

Simulation of braking of an automotive vehicle with electric drive motor during downhill run

100%

Frąckowiak J.

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2006

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tom No 52

181-186

EN

The paper presents a simulation of braking of an automotive vehicle while downhill running with electric power recovery. The automotive vehicle is driven with a three-phase induction motor supplied from an accumulator battery through a voltage inverter. Mathematical model of the vehicle is described by voltage-current equations of an induction motor, the equation of motion of the vehicle, resistance to motion taking a form of a trinomial square, voltage converter of uni-polar regular modulation of pulse width, and the accumulator battery. The mechanical losses and the losses arising in the magnetic circuit of the induction motor are considered.

4

Structural and Mössbauer spectroscopy studies of metallic powders Fe-Al-Cr-X (X =Ni, Mo) obtained by the self-decomposition method

45%

Hanc A. , Frąckowiak J. , Binczyk F. , Dercz G. , Pająk L.

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2008

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tom Vol. 29, nr 2

86-88

EN

The Fe-Al-Cr and Fe-Al-Cr-X X=(Ni,Mo) metallic powders produced by the self-decomposition method were examined by X-ray powder diffraction, scanning electron microscopy and Mössbauer spectroscopy. The determined crystal structure parameters and the hyperfine interaction parameters are presented and discussed. The results of solute addition (X = Ni, Mo) in the investigated Fe-Al-Cr metallic powders are presented and discussed. The nickel and molybdenum additions modifies the phase composition of the studied materials and changes hyperfine parameters. The investigated Fe-Al-Cr powders produced by the self-decomposition method contain two phases, both of the B2 type structure: Fe(Cr)AlX and Cr(Fe)AlX enriched in Fe and Cr respectively and as well small amount of FexCr1- x. The Fe-Al-Cr-X (X =Ni, Mo) metallic powders and contain the besides the main Fe2Al5(X) phase and (FeX)Al8Cr5 phase. X-ray diffraction and SEM studies confirm the results of the Mössbauer spectroscopy.

PL

W pracy przedstawiono wyniki badań struktury, mikrostruktury oraz parametrów oddziaływań nadsubtelnych proszków metalicznych Fe-Al-Cr oraz Fe-Al-Cr-X X = (Ni, Mo) o składzie zestawionym w tabeli 1. Badania przeprowadzono stosując metodę dyfrakcji rentgenowskiej, skaningowej mikroskopii elektronowej oraz spektroskopii efektu Mössbauera. Wykazano, że proszki metaliczne Fe-Al-Cr stanowiąmateriał dwufazowy. Zidentyfikowane fazy Fe(Cr)AlX i Cr(Fe)AlX zawierają zmienną koncentrację atomów żelaza oraz chromu, przy czym każdą z faz charakteryzuje uporządkowana struktura typu B2. Wyniki badań analizy dyfraktogramów oraz mikroanalizy rentgenowskiej wykazały także występowanie drobnych wydzieleń fazy FexCr1-x. Wprowadzone atomy domieszek modyfikują strukturę badanych materiałów. Proszki metaliczne Fe-Al-Cr-X (X = Ni, Mo) są materiałem wielofazowym stwierdzono występowanie faz na osnowie międzymetalicznej Fe2Al5. W badanych proszkach metalicznych stwierdzono występowanie fazy Fe2Al5(X) oraz (FeX)Al8Cr5, każda z tych faz zawiera w swoim składzie zastosowane domieszki - nikiel oraz molibden. Metodą spektroskopii efektu Mössbauera izotopu 57Fe określono parametry oddziaływań nadsubtelnych, tj. przesunięcie izomeryczne-(IS) oraz rozszczepienie kwadrupolowe-(QS) (tab. 2), charakteryzujące zidentyfikowane na podstawie badań strukturalnych faz.

5

Effect of tungsten content on microstructure and magnetic properties of nanocomposite Nd10Fe84-xWxB6 (0

45%

Przybył A. , Wysłocki J. J. , Leonowicz M. , Kaszuwara W. , Frąckowiak J.

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2006

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tom Vol. 27, nr 2-3

85-99

EN

The investigation was carried out on nanocomposite Nd10Fe84-xWxB6 magnets with different tungsten content (from 0 to 33 at.%) produced by the mechanical alloying method. The alloys have a fine grained and highly porous structure. As tungsten is added the powder particles become progressively smaller and are distributed uniformly throughout the whole specimen volume. From the phase structure determination using X-ray diffraction, Moessbauer spectroscopy and transmission electron microscopy it has been found that with the increase of tungsten content in the magnets the amount of the magnetically hard Nd2Fe14B and the soft alpha-Fe phases decrease. Instead, paramagnetic phases appear. Moreover, the addition of tungsten to the basic composition results in a significant increase in coercivity jHc (from 260 to 1350 kA/m) and a reduction in both the remanence Br (from 0.95 to 0.24 T) and the maximum magnetic energy product (BH)max (from 80 to 13 kJ/cubic m).

6

Mössbauer and structure studies on metallic powders from Fe-Al-X (X = Ni, Cu, Cr)

45%

Hanc A. , Dercz G. , Pająk L. , Frąckowiak J. , Kansy J.

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2008

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tom Vol. 31, nr 1

20-24

EN

Purpose: The Fe-Al-X and Fe-Al-Ni-X metallic powders produced by the self-decomposition process and then intensive grinding in an electro-magneto-mechanical mill with X = Fe, Ni, Cu, Cr additions was determined by applying the X-ray powder diffraction (XRD) and Mössbauer spectroscopy. Design/methodology/approach: The X-ray diffraction and Mössbauer spectroscopy were applied to identify the phase composition of the studied materials. Ordering process was analyzed by X-ray diffraction methods and Mössbauer spectroscopy. Findings: The effects of solute addition (X = Fe, Ni, Cu, Cr) in the investigated Fe-Al and Fe-Al-Ni metallic powders are presented and discussed. Good correlation between the results of X-ray diffraction and Mössbauer spectroscopy studies was obtained. Research limitations/implications: The Mössbauer spectroscopy appeared to be usefull in the identification of phase composition in studied materials. Application of Rietveld refinement method enabled the verification of this composition. Practical implications: The information on the phase transformation during the self-decomposition process and then intensive grinding in an electro-magneto-mechanical mill with additions are of prime importance for technological processing. Originality/value: All the phases that exist in the milled material contain high concentrations of aluminium (over 50 at. %) and have the ordered B2 structure. Alloying additions (Ni, Fe, Cu, Cr) and intensive high-energy grinding in the EMM mill modified the chemical and phase composition of the Fe-Al-X and Fe-Al-Ni-X samples.