Wyniki wyszukiwania - BazTech

1

The Influence of the Casting Process on Shaping the Primary Structure of Mg-Li Alloys

Bednarczyk Iwona

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 4

137--144

EN

This paper presents the results of a study to determine the influence of casting parameters (cooling rate in the casting mould, casting temperature) on the primary structure of Mg-4%Li-1%Ca alloy ingots. The macro- and microstructure analysis of the Mg-4%Li-1%Ca alloy was performed using light and electron microscopy techniques. Microhardness measurements were made for the Mg-4%Li-1%Ca alloy and phase identification in the Mg-4%Li-1%Ca alloy was made using X-ray phase analysis.

2

Metallurgical analysis of the causes of failure of the hardening furnace conveyor belt

Merda A., Klimaszewska K., Sroka M., Golański G.

Archives of Materials Science and Engineering

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2019

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Vol. 98, nr 2

68--73

EN

Purpose: The aim of the tests was to analyze the microstructure and mechanical properties of a section of the hardening furnace conveyor belt serviced at the temperature of 880-920°C in the carburizing atmosphere, in the context of determining the probable causes of its failure. Design/methodology/approach: The scope of performed tests included: chemical composition analysis of the steel and particles, microstructure investigated using optical and scanning electron microscopy, X-ray phase analysis. Findings: The analysis of the chemical composition showed that the examined material was austenitic steel X15CrNiSi25-21 (S310). Performed metallurgical tests showed that after the service the examined steel was characterized by austenitic structure with numerous precipitates of diverse morphology. In the structure the sigma phase particles and probably the M23C6 carbides precipitates were observed. The continuous grid of precipitates on the boundaries of grains (mainly the sigma phase) and the influence of the cyclic changing heat loads (or thermo-mechanical loads) were the main causes of failure of the analysed detail. Research limitations/implications: The aim of the work was to determine the probable causes of damage of the material used for a conveyor belt of a hardening furnace. Practical implications: The results of investigation and analysis of the metallographic of het-resisting austenitic steel X15CrNiSi25-21 (S310) after service at the temperature of 880-920°C are presented. Originality/value: The paper presents the results of research on the microstructure and mechanical properties of the section of hardening furnace conveyor belt made of creepresisting austenitic steel. The aim of the performed tests was to determine the probable causes of damage of the analysed detail.

3

Mikrostruktura natapianej powłoki Ni-Cr-B-Si

Kondej A., Babul T.

Przegląd Spawalnictwa

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2016

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R. 88, nr 3

23--26

PL

Stopy Ni-Cr-B-Si są stosowane do lutowania twardego oraz do modyfikacji powierzchni w celu zwiększenia odporności na zużycie ścierne. Lutem twardym z tej grupy jest BNi-2, stosowany do łączenia stali nierdzewnych, żaroodpornych stopów niklu oraz stali stopowych. W pracy lut BNi-2 w postaci folii wykorzystano jako materiał powłokowy. Stop po natopieniu i wygrzaniu w piecu próżniowym tworzy wielofazową powłokę. Celem pracy było opisanie mikrostruktury powłoki. Wyniki badań wskazują na występowanie czterech obszarów o różnej morfologii. Wykazano obecność roztworu stałego na bazie niklu, borków niklu, borków chromu oraz krzemków niklu.

EN

The Ni-Cr-B-Si alloys are used for brazing and for surface modification to increase the wear resistance. The brazing alloy from this group is BNi-2, used for joining stainless steels, heat-resistant nickel alloys and alloy steels. In the work the brazing alloy BNi-2 in foil form was used as a coating material. The alloy after surfacing and soaking in a vacuum furnace forms a multiphase coating. The purpose of this work was to describe the microstructure of the coating. The results indicate on the incidence of four areas of different morphology. The presence of the solid solution based on nickel, nickel borides, chromium borides and nickel silicides was demonstrated.

4

X-Ray Phase Analysis of Nitrided Layers of X2CrNiMo17-12-2 Austenitic Steel

Frączek T., Olejnik M., Pilarska M.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 3A

2005--2012

EN

This work presents the results of diffraction analyses carried out using X-ray phase analyses (XRD and GIXRD) of nitrided layers of X2CrNiMo17-12-2 austenitic steel. Plasma nitriding process was c arried out in the temperature range of 325 ÷ 400 °C and time of 2 ÷ 4 h. Hydrogen-nitrogen plasma was used as reactive atmosphere (H2 75% + N2 25%) with pressure of 150 Pa. On the basis of the X-ray analyses it was stated that the obtained nitrided layers consisted of a subsurface layer of chromium nitrides and a zone of nitrogen saturated austenite.

PL

W pracy zaprezentowano wyniki badań strukturalnych metodą rentgenowskiej analizy fazowej (XRD i GIXRD) warstw azotowanych na podłożu stali austenitycznej X2CrNiMo17-12-2. Proces azotowania jarzeniowego przeprowadzono w zakresie temperatur 325 ÷ 400 °C i czasu 2 ÷ 4 h. Atmosferę reaktywną stanowiła plazma wodorowo-azotowa (H2 75% + N2 25%) o ciśnieniu 150 Pa. Na podstawie badań rentgenowskich stwierdzono, że otrzymane warstwy azotowane składają się z przypowierzchniowej warstwy azotków chromu oraz strefy austenitu przesyconego azotem. Zastosowanie ekranu aktywnego spowodowało wzrost głębokości dyfuzji azotu w głąb azotowanej powierzchni oraz zwiększyło jego koncentrację w fazie austenitu przesyconego azotem.

5

Morphology of nickel aluminate spinel (NiAl2O4) formed in the Al2O3-Ni composite system sintered in air

Zygmuntowicz J., Miazga A., Konopka K.

Composites Theory and Practice

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2014

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R. 14, nr 2

106--110

EN

The aim of this paper was to characterize the microstructure, especially the morphology of NiAl2O4 spinel phase in Al2O3-Ni composite system. The composites were prepared from the powder mixture contains: 90 vol. % of Al2O3 and 10 vol. % of nickel powder. Two series of samples were prepared: Series I with addition of nickel powder of average particle size 8.5 µm and Series II with addition of nickel powder of average particle size 1.5 µm. The presence of the spinel phase in composites was confirmed by both Xr-ay phase analysis and SEM observations. All tested samples were characterized by homogeneous distribution of NiAl2O4 phase in the whole volume of the material. The spinel has on oval shape with characteristic void inside. Two areas of spinel phase were identificated. The inner part is compact and consisted of large grains of spinel. In contrast, the outer part is porous and consisted of smaller grains of spinel. In aim to describe the spinel morphology the stereological analysis was done. Results showed that there is no evident influence of Ni initial grain powder size on the spinel formation and morphology. Formation of the spinel retarded the densification of the composites of Al2O3-Ni system.

PL

Celem niniejszej pracy była charakterystyka mikrostruktury, w szczególności morfologii fazy spinelowej NiAl2O4 w kompozytach z układu Al2O3-Ni. Wykonano dwie serie próbek różniących się między sobą średnią wielkością wyjściowo zastosowanych cząstek proszku niklu. Do przygotowania Serii I wykorzystano nikiel o średniej wielkości cząstek 8,5 µm, natomiast w II Serii użyto cząstek o średniej wielkości 1,5 µm. Na podstawie obserwacji SEM stwierdzono obecność fazy spinelowej w każdej z badanych serii, potwierdziły to również wyniki rentgenowskiej analizy fazowej badanych kompozytów. Wszystkie badane spieki cechowały się jednorodnym rozmieszczeniem fazy NiAl2O4 w całej objętości kompozytu. Faza spinelowa posiada owalny kształt z pustką w środku. Wyróżnić można dwa obszary. Wewnętrzny obszar spinelu jest zwarty i składa się z dużych ziaren spinelu. Przeciwnie, zewnętrzny obszar jest porowaty i złożony z drobniejszych ziaren spinelu. Do opisu morfologii spinelu została użyta analiza stereologiczna. Na podstawie tej analizy stwierdzono, że rozmiar użytego proszku Ni nie wpływa na formowanie i morfologię wytworzonego spinelu. Ponadto stwierdzono, że obecność fazy spinelowej utrudnia zagęszczenie kompozytu.

6

Influence of pulse laser irradiation on structure and mechanical properties of amorphous Fe73.1Nb3Cu1.0Si15.5B7.4 alloy

Mudry S.I., Nykyruy Yu.S., Kulyk Yu.O., Stotsko Z. A.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 61, nr 1

7--11

EN

Purpose: The aim of this work was to study structure changes in Fe-based amorphous ribbon under laser radiation, determine it dependence from laser treatment parameters and establish the correlation between structure and microhardness. Design/methodology/approach: Amorphous ribbons of Fe73.1Nb3Cu1.0Si15.5B7.4 alloy, obtained by rapid cooling from the melt, has been treated by pulsed laser radiation with wavelength λ = 1.06 μm and pulse duration τ = 130 ns. Structure transformation has been studied by means of X-ray diffraction method, which allowed us to determine the phase composition, volume fraction and grain size of crystalline phases has been determined. Findings: It has been shown, that laser treatment method allows forming an amorphous-nanocrystalline composite. It was found that microhardness of ribbon increases after irradiation and linearly depends on percent of crystalline phase. Practical implications: Laser treatment can be used as an substitute of isothermal heat treatment to produce amorphous-nanocrystalline materials with improved properties. Originality/value: The originality of this work is based on applying of pulse laser irradiation for modifying structure of amorphous Fe73.1Nb3Cu1.0Si15.5B7.4 alloy.

7

Struktura warstw krzemowanych wytwarzanych metodą kontaktowo- -gazową na niobie i stopie niobu

Zawadzki M., Swadźba L., Mendala B., Moskal G., Witala B., Swadźba R., Toczek S.

Inżynieria Materiałowa

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2013

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Vol. 34, nr 6

921--924

PL

W pracy przedstawiono wpływ czasu procesu wygrzewania dyfuzyjnego na mikrostrukturę, skład chemiczny i fazowy warstw krzemkowych wytworzonych na podłożu z niobu oraz ze stopu niobu C-103. Krzemowanie dyfuzyjne prowadzono metodą kontaktowo-gazową w temperaturze 1050°C przez 24 oraz 70 h, w atmosferze argonu. Warstwy krzemkowe otrzymane na podłożu z niobu miały budowę dwustrefową (rys. 1, 3). Składały się ze strefy zewnętrznej charakteryzującej się wyraźną strukturą kolumnową oraz strefy wewnętrznej o jednolitej strukturze. Warstwy krzemkowe otrzymane na podłożu ze stopu niobu C-103 charakteryzowały się budową trzystrefową (rys. 2, 4). Strefa zewnętrzna i wewnętrzna miała budowę kolumnową. W strefie środkowej stwierdzono nierównomiernie rozłożone wydzielenia. Przeprowadzono mikroanalizę składu chemicznego oraz analizę składu fazowego. Stwierdzono obecność krzemku niobu NbSi2 w strefie zewnętrznej oraz Nb5Si3 w strefie wewnętrznej warstw (rys. 8÷10). Otrzymane fazy były zgodne z wykresem równowagi Nb-Si.

EN

This paper presents the influence of pack-cementation process time on the microstructure, chemical and phase composition of Si coatings formed on niobium and Nb-based alloy C-103 substrate. Pack siliconizing process was carried out at temperature 1050°C for 24 and 70 hours in argon protection atmosphere. The Si coatings formed on niobium substrate had two layers structure (Fig. 1, 3). The coatings consist of outer layer that is characterized by fairly columnar structure and inner layer with uniform structure. The Si coatings formed on Nb-based alloy C-103 substrate is characterized by three layers structure (Fig. 2, 4). The outer and inner layer had uniform columnar structure. The unevenly distributed particles was found in the middle layer of the Si coating. EDS microanalysis and the X-ray phase analysis was carried out. It was found presence of NbSi2 niobium silicide in the outer layer and Nb5Si3 niobium silicide in the inner layer of the Si diffusion coatings (Fig. 8÷10). The obtained phased were consistent with the equilibrium diagram Nb-Si.

8

High-energy milling as a method for obtaining tetragonal form of PbO

Staszewski M., Myczkowski Z., Bilewska K., Sosiński R., Lis M., Czepelak M., Kołacz D.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 52, nr 1

39--46

EN

Purpose: The aim of this work was to verify the usefulness of high-energy milling, using electromagnetic mill, as a method for obtaining tetragonal (red) form of PbO, alternative to standard methods. Design/methodology/approach: Experiments were held to compare samples of the yellow form of PbO after milling in electromagnetic mill with the ones milled in high-energy planetary ball mill as a function of grinding medium (sticks or balls) to powder mass ratio, milling duration and instrumental conditions. Findings: Quantitative X-ray diffraction and analysis of granulation of mill products were applied. The characteristics of structural transitions of studied powder depending on milling conditions were defined. Practical implications: Utilization of electromagnetic mills was found to be suitable for milling of PbO. The speed and unit price of this process assure competitiveness of the method to standard methods. Tested method of high-energy milling assures possibility to supply, in certain conditions, good product. Obtained product may be used for manufacturing of minium. Originality/value: Optimum conditions of milling process and milling limitations were determined. Suggestions regarding optimization of mill construction were presented.

9

Mikrostruktura, skład fazowy i mikrotwardość warstw boroniklowanych modyfikowanych wiązką laserową

Bartkowska A., Pertek A., Jankowiak M., Jóźwiak K., Klimek L.

Inżynieria Materiałowa

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2012

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Vol. 33, nr 1

32--36

PL

W pracy przedstawiono wyniki laserowej modyfikacji warstw boroniklowanych wytworzonych na stali konstrukcyjnej C45. Proces boroniklowania składał się z galwanicznego niklowania oraz borowania dyfuzyjnego. Laserową obróbkę cieplną (LOC) przeprowadzono za pomocą lasera CO 2 o mocy nominalnej 2600 W. Zbadano wpływ prędkości posuwu wiązki laserowej na mikrostrukturę i mikrotwardość warstwy wierzchniej. Do analizy fazowej warstw boroniklowanych wykorzystano dwie metody: dyfrakcję elektronów wstecznie sprężyście rozproszonych (EBSD) oraz rentgenowską analizę fazową. Badania wykazały, że występują w niej fazy: (Fe, Ni)B, (Fe, Ni) 2B, Ni4B3, Ni3B. Mikrotwardość warstwy wierzchniej po boroniklowaniu i laserowej obróbce cieplnej zmniejszyła się do ok. 1300÷700 HV w zależności od parametrów LOC w porównaniu z warstwą tylko boroniklowaną o mikrotwardości 1600÷1800 HV.

EN

The paper presents the results of laser surface modification of boronickelized layers produced on C45 constructional steel. The process was composed of nickel plating followed by diffusion boronizing. Laser heat treatment (LHT) was carried out with a CO2 laser of a nominal power of 2600 W. The results present the influence of the laser beam scanning rate on the microstructure and microhardness of the surface layer. For the phase analysis of the boronickelized layer, two methods were employed: Electron Back-Scatter Diffraction (EBSD) analyses and X-ray phase analysis. The results showed that the boronickelized layer was composed of FeB, (Fe, Ni)2B, (Fe, Ni)4B3, Ni3B. The microhardness of the surface layer after boronickelizing and laser heat treatment was reduced to about 700÷1300 HV, depending on the LHT parameters, compared to only a boronickelized layer with a microhardness of 1600÷1800 HV.

10

Analiza strukturalna i fazowa warstw borowanych modyfikowanych niklem i chromem

Bartkowska A., Pertek A., Miklaszewski A.

Inżynieria Materiałowa

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2012

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Vol. 33, nr 5

448--451

PL

W pracy przedstawiono wpływ modyfikacji niklem i chromem na strukturę warstwy borowanej wytworzonej na stali C45. Warstwy modyfikowane wytworzono metodą galwaniczno-dyfuzyjną. Powłokę niklu lub chromu otrzymano metodą elektrochemiczną. Następnie przeprowadzono proces borowania dyfuzyjnego w temperaturze 950°C oraz 1050°C przez 4 h. Warstwa borowana po modyfikacji miała budowę dwustrefową (rys. 1÷4, 6, 8). Składała się z ciągłej strefy przypowierzchniowej i iglastych borków żelaza. Przeprowadzono rentgenowską analizę fazową. Stwierdzono obecność borków żelaza i borków niklu w warstwach modyfikowanych niklem (rys. 5) oraz borków żelaza i borków chromu w warstwach modyfikowanych chromem (rys. 9). Otrzymane fazy były zgodne z wykresami równowagi Fe-B, Ni-B oraz Cr-B. Mikroanaliza EDS wykazała obecność pierwiastka modyfikującego w ciągłej strefie przypowierzchniowej (rys. 3, 7).

EN

The paper presents the influence of modification of nickel and chromium on the structure of borided layer produced on C45 steel. Modified layers were produced by galvanic-diffusion method. Nickel or chromium coating was obtained by electroplating method. Afterwards, the diffusion boriding pro- cess was carried out at temperature 950°C and 1050°C for 4 h. The borided layer after modification had dual-zone structure (Fig. 1÷4, 6, 8). It consisted of a continuous surface zone and coniferous iron borides. The X-ray phase analysis was carried out. It was found presence of iron and nickel borides phases in layers modified with nickel (Fig. 5) and iron and chromium borides phases in layers modified with chromium (Fig. 9). The obtained phases were consistent with the equilibrium diagrams Fe-B, Ni-B and Cr-B. EDS microanalysis showed the presence of the modifying element in continuous surface zone (Fig. 3, 7).

11

Zastosowanie nieniszczących dyfrakcyjnych metod rentgenowskich do charakteryzowania stanu struktury materiałów

Skrzypek S. J., Witkowska M., Kowalska M., Chruściel K.

Hutnik, Wiadomości Hutnicze

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2012

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Vol. 79, nr 4

238--246

PL

Artykuł przedstawia niektóre istotne zastosowania metod rentgenowskich do określania wybranych właściwości i charakterystyk materiałowych odnoszących się do struktury i stanu materiałów po różnych etapach procesu wytwarzania i obróbki. Te nieniszczące metody, które wykorzystują dyfrakcję promieni rentgenowskich, dają w pośredni sposób możliwość ujawniania szeregu danych dotyczących struktury wewnętrznej, jak również pomiaru niektórych podstawowych właściwości materiałów. Typowe zastosowania obejmują pomiary mikroi makro-naprężeń własnych, grubości cienkich warstw i powłok, składu fazowego, gęstości defektów struktury, rozmiaru krystalitów oraz ich rozkładu orientacji (tekstury) itp. Prezentowane metody i techniki rentgenowskie wykorzystują szeroki zakres stosowanych długości fali oraz różne warianty geometrii dyfrakcji. W artykule uwzględniono zwłaszcza metody dyfrakcji promieniowania X w geometrii stałego kąta padania (SKP) oraz metodę Bragg-Brentano (BB) stosowane do praktycznego pomiaru grubości powłok i cienkich warstw. Takie nieniszczące pomiary mają aspekt praktyczny, np. w zastosowaniu do kontroli jakości produkcji lub poszczególnych operacji technologicznych, a także do diagnozowania stopnia zużycia eksploatacyjnego elementów maszyn.

EN

The paper presents some important applications of X-ray methods in determination of selected material features and characteristics related to the structure and state of materials after different stages of manufacturing and processing. These non-destructive methods, which base on diffraction of X-rays, give ability to reveal indirectly a number of details of internal structure and to measure some important materials features. Typical applications comprise measurements of micro- and macro- residual stresses, thickness of thin layers and coatings, phase composition, density of lattice defects, size of crystallites and their orientation distribution (texture), etc. The presented X-ray methods and techniques utilize wide range of applicable wavelengths and different variants of diffraction geometry. Especially symmetrical and asym-- metrical Bragg-Brentano method, the methods with grazing incidence angle and reflectivity in different conditions were considered in the paper. In particular the last two methods are destined to thickness measurements of micro- and nano- thin layers and surface coatings. Such X-ray non-destructive methods are recommended for practical applications in quality control of production as well as verification of exploitative and operational wear of machine elements.

12

Wear resistance of aluminized steel plates

Żaba K.

Archives of Metallurgy and Materials

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2011

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Vol. 56, iss. 4

871-882

EN

The results of the abrasion resistance measurements of aluminized steel strips are presented in the hereby paper. Steel strips of DX52D+AS120 grade, before and after a heat treatment at temperatures of 200-1000 C for 1 – 5760 minutes, were tested. Tests of the abrasion resistance were carried on in a specially built device: rotating disk – sample performing a plane-rotary motion, with an application of a lubricating medium. Examinations of the abrasion resistance were also performed by means of the block-on-ring tester. Estimations of a coating mass loss, roughness and thickness changes were carried on. The obtained results are illustrated by diagrams and macro- and micro-observations. Phase analysis investigations were also performed on samples selected after the abrasibility testing. The range of the heat treatment parameters – after which the Al-Si coating increased its abrasion resistance – was estimated.

PL

W artykule przedstawiono wyniki badan odpornosci na ścieranie aluminiowanych tasm stalowych. Badaniom poddano taśmy stalowe z gatunku DX52D+AS120 przed i po obróbce cieplnej w temperaturze 200-1000 C w czasie 1min-5760min. Wykonano badania odporności na ścieranie w specjalnie przygotowanym urzadzeniu typu obracająca się tarcza – próbka, wykonujaca ruch posuwisto-zwrotny, przy zastosowaniu środka smarujacego Zrealizowano także badania odporności na zużycie cierne za pomocą testera typu rolka-klocek. Dokonano oceny ubytku masy, zmian chropowatoąci i grubości powłoki. Wyniki badan zobrazowano za pomocą wykresów oraz makro i mikro obserwacji. Przeprowadzono także badania analizy fazowej na próbkach wytypowanych po badaniach ścieralności. Określono taki zakres parametrów obróbki cieplnej, po której następuje wzrost odporności na ścieranie powłoki Al-Si.

13

Formation and structure of Co50Cr15Mo14C15B6 bulk metallic glasses

Nowosielski R., Witrak A.

Archives of Materials Science and Engineering

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2009

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Vol. 36, nr 1

28-33

EN

Purpose: In the present paper thermal stability and structure of Co50Cr15Mo14C15B6 (numbers indicate at.%) glassy alloys were investigated. Design/methodology/approach: The following experimental techniques were used: scanning electron microscopy (SEM) and X-ray diffraction (XRD) phase analysis method to the test the structure. The thermal properties associated with crystallization temperature of the glassy samples were measured using differential thermal analysis and differential scanning calorimetry. Findings: The structural studies revealed an amorphous structure for the rods with thicknesses up to 3 mm, regardless of their thickness. Research limitations/implications: During thermal activation of metallic glasses two processes can be distinguished: structural relaxation and complex relaxation process of the alloy. Practical implications: The Co-rich amorphous alloys have attracted great interest for a basic research on the materials as well as for variety application. Originality/value: The obtained results confirm the utility of applied investigation methods in the thermal and structure analysis of examined amorphous alloys.

14

X-ray and SEM studies on zirconia powders

Dercz G., Prusik K., Pająk L.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 31, nr 2

408-414

EN

Purpose: The microstructure characterization of commercially available zirconia powders was the purpose of this paper. Different methods of structure analysis were applied owing to the complex, multiphase structure of studied materials. Design/methodology/approach: The X-ray diffraction (XRD) and scanning electron microscopy (SEM) investigations were performed on three commercial zirconia ceramic materials: Amdry 204 NS (ZrO2~ 8 wt.% of Y2O3), Metco C8 YZ (ZrO2~ 8 wt.% of Y2O3) and Metco 202 (ZrO2~ 20 wt.% of Y2O3). The Rietveld method appeared to be very useful in the verification of the qualitative phase composition and in the determination of phase abundance. Hill and Howard procedure was applied for quantitative phase analysis. The parameters of the individual diffraction line profiles were determined by PRO-FIT Toraya procedure. The powder morphology was analyzed by SEM method. Findings: In the Amdry sample comparable contents of two phases: monoclinic (44.1 wt.%) and cubic (55.9 wt.%) was stated by XRD analysis. The presence of Y2O3 phase besides of monoclinic, tetragonal and cubic ZrO2 ones were stated for both Metco samples. The tetragonal phase (55.2 wt.%) was found to be the main component of the Metco C8-YZ sample whereas the content of Y2O3 is the lowest (2.7 wt.%). On the other hand cubic phase (68.2 wt.%) was the main component of the Metco 202 sample and the content of Y2O3 is again the lowest (4.5 wt.%). The SEM images of all the samples reveal the spherical shape of powder particles. The morphology of both Metco samples is quite similar. For Metco 202 sample the hierarchical type structure of powder particle is observed; the greater particles contain smaller ones. The shell of particles is composed of distinct patches. On the other hand the structure of spherical particles of Amdry sample is of branched, rather dense skeleton type. From X-ray diffraction data it can be concluded that the crystallite size of all involved phases lies above nanoscale. Practical implications: Performed studies enable the determination of the relation between the microstructure of commercial powders and their utilisable properties. Originality/value: The applied, different methods of structure analysis appeared to be very useful in the microstructure analysis of complex, multiphase material.

15

Microstructure of polymer composite with barium ferrite powder

Nowosielski R., Babilas R., Dercz G., Pająk L.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 31, nr 2

269-274

EN

Purpose: The aim of the paper is the microstructure characterization of commercial BaFe12O19 powder and its composite material in polymer matrix; XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscopy) methods were applied. Design/methodology/approach: The Rietveld method appeared to be very useful in the verification of the qualitative phase composition and in the determination of phase abundance. Hill and Howard procedure was applied for quantitative phase analysis. The parameters of the individual diffraction line profiles were determined by PRO-FIT Toraya procedure. The morphology of barium ferrite powders and a fracture surface of the examined composite material was analyzed using the scanning electron microscope. Findings: The X-ray diffraction analysis enabled the identification of BaFe12O19 and Fe2O3 phases in examined material. Basing on Rietveld and Toraya methods the determination of lattice parameters, crystallite size and the lattice distortion was performed. Distribution of powders of barium ferrite in polymer matrix is irregular and powder particles are of irregular shapes and different sizes. Research limitations/implications: Maked researches are limited only to characterization the microstructure of commercial material, because obtained results will be helpful to prepare barium ferrite powders by mechanical alloying and subsequent annealing in the future. As prepared BaFe12O19 powders will be used as the starting material for magnets bonded with polymer material. Originality/value: The obtained results of investigations by different methods of structure analysis confirm their useful in the microstructure analysis of powder materials.

16

Microstructure and magnetic properties of BaFe12O19 powder

Nowosielski R., Babilas R., Dercz G., Pająk L., Skowroński W.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 27, nr 1

51-54

EN

Purpose: Analysis of microstructure and magnetic properties of BaFe12O19 powder obtained by milling and annealing of Fe2O3 and BaCO3 precursors. Design/methodology/approach: The mixture of iron oxide (Fe2O3) and barium carbonate (BaCO3) powders was used to obtain BaFe12O19 powder by using high-energy ball milling and heat treatment processes. The X-ray diffraction methods were used for qualitative, quantitative phase analyses and for crystallite size and lattice distortion determination. The thermal properties of the studied powders were analyzed using the differential thermal analysis (DTA). The magnetic properties of examined powder material were studied by resonance vibrating sample magnetometer (R-VSM). The size of powder particles was determined by a laser particle analyzer. Findings: The milling process of iron oxide and barium carbonate mixture causes decrease of the crystallite size of involved phases. The X-ray diffraction investigations of Fe2O3 and BaCO3 mixture milled for 50 hours and annealed at 850, 900, 950 and 1000*C enabled the identification of hard magnetic BaFe12O19 phase and also small amount of Fe2O3 phase. The magnetic properties of studied powders are dependent on temperature of their annealing. The sample annealed at 1000*C has the best hard magnetic properties from all studied samples. The content changes of hard magnetic phase (BaFe12O19) with the increase of annealing temperature results in the improvement of hard magnetic properties. Practical implications: The BaFe12O19 powder can be suitable component to produce sintered hard magnetic materials. Originality/value: The study results of BaFe12O19 powders confirm the utility of applied investigation methods in the microstructure and magnetic properties analysis of powder materials.

17

Ordering process of Fe28Al and Fe28Al5Cr alloys

Pająk L., Kansy J., Hanc A., Dercz G., Jabłońska M.

Archives of Materials Science and Engineering

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2008

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Vol. 30, nr 2

81-84

EN

Purpose: The comparison of ordering process in Fe28Al and Fe28Al5Cr alloys annealed for 8, 16 and 48 hours at 1000°C was performed. The composition of studied alloys is closed to one of Fe3Al phase. Design/methodology/approach: The studied alloys were melted in induction furnace under vacuum. Next the alloys were gravitatively casted into cylindrical graphite moulds. The alloy samples were annealed at 1000°C for 8, 16 and 48 hours. The ordering process was analyzed by X-ray diffraction,Mössbauerspectroscopy and positron annihilation methods. Findings: Different behaviour of Fe28Al and Fe28Al5Cr alloys during annealing for 8, 16 and 48 hours at 1000°C was found. The Fe3Al phase of DO3 type structure was stated only in the sample of Fe28Al alloy annealed for 48 hours. The FeAl phase appeared to be the main phase in the other samples. Research limitations/implications: The applied investigation methods appeared to be useful in the studies of long range ordering process. Application of Rietveld refinement method enabled the verification of qualitative phase analysis and the determination of lattice constant parameters. Relatively great grain sizes in studied samples made the exact determination of long range ordering parameters difficult. Practical implications: The information on the phase transformation during the heat treatment of alloys, including long range ordering, are of prime importance for technological processing. The structures with long range ordering significantly affect the properties of alloys with intermetallic phases. Originality/value: Good correlation between the results of X-ray diffraction, Mossbauer spectroscopy and positron annihilation methods were obtained. Addition of chromium made the long range ordering process slower.

18

Identification of precipitations in anodically dissolved high-strength microalloyed Weldox steels

Ozgowicz W., Kurc A., Nawrat G.

Archives of Materials Science and Engineering

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2008

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Vol. 31, nr 2

95-100

EN

Purpose: The aim of the investigations is to elaborate the optimum conditions of anodic dissolutions from highstrength microalloyed Weldox steels in order to obtain indispensable quantities of electrolytic extractions and to identify them by X-ray phase analysis. Design/methodology/approach: Anodic dissolution of steel was carried out according to the potentiostatic method. In the X-ray qualitative analysis the comparative method was applied. The corrosion resistance of steels was determined by means of the first method of Stern - Tafel. Findings: The activity of anodic dissolution of the investigated steel was determined in various solutions of electrolytes with different pH and a different complexive affect versus iron. Practical implications: It has been found that the application of an optimal reagent for the anodic dissolution of Weldox Steel and of the chronopotentriometric method permit to get the required mass of electrolytic extraction for the qualitative X-ray phase analysis. Electrochemical investigations permitted also to assess preliminarily the corrosion resistance of the investigated steels. Originality/value: It has been found that there exists a distinct relation between the mass of electrolytic extractions and the kind of the dissolved precipitation and the value of the electrochemical potential of the anodic dissolution of steel, which affects essentially the result of the X-ray phase analysis. Besides, a high corrosion resistance of the investigated steels to the destructive effect of a saline environment and a low resistance to an acid environment have been detected.

19

Microstructure investigations of Co-Si-B alloy after milling and annealing

Nowosielski R., Babilas R., Dercz G., Pająk L.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 23, nr 1

59-62

EN

Purpose: The work presents the microstructure characterization of Co77Si11,5B11,5 metallic glass after high-energy ball milling and heat treatment processes. Design/methodology/approach: The studies were performed on ribbon prepared by melt spinning and this ground in high-energy vibratory ball mill. The tested ribbon and obtained powders were also annealed in specified heat treatment conditions. The morphology of the powder particles of milled ribbon was analyzed by using the confocal laser scanning microscope. The methods of X-ray diffraction were used for the qualitative phase analysis. The parameters of the individual diffraction line profiles were determined by PRO-FIT Toraya procedure. The average crystallite sizes and lattice distortions for Co phase were estimated using Williamson-Hall method. Findings: The studied Co77Si11,5B11,5 metallic glass in annealed state contains hexagonal Co crystalline phases emerged in amorphous matrix. The crystallite size of Co phase in as-cast sample lies in nanoscale. After annealing process the crystallite size increases to 72 nm and diminishes to 46 nm in the powder sample after 30 hours of milling. The milling causes decrease of the crystallite size and increase of lattice distortions of crystalline phase. The powder particles after 30 hours of milling are of spherical shape. Practical implications: The powder particles obtained after milling process of Co-based metallic glass could be suitable components in production of ferromagnetic nanocomposites. Originality/value: The obtained results confirm the utility of applied investigation methods in the microstructure analysis of powder materials with nanocrystalline phases.

20

Microstructure and mechanical properties of AC AlSi9CuX alloys

Dobrzański L. A., Maniara R., Krupiński M., Sokolowski J. H.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 24, nr 2

51-54

EN

Purpose: In order to gain a better understanding of how to control the as-cast microstructure, it is important to understand the evaluation of microstructure during solidification and understanding how influence the changes of chemical concentration on this microstructure and mechanical properties. In this research, the effect of Cu content on the microstructure and mechanical properties of AC AlSi9CuX series alloys has been investigated. Design/methodology/approach: The experimental alloy used in this investigation were prepared at the University of Windsor (Canada) in the Light Metals Casting Laboratory, by mixing the AC AlSi5Cu1(Mg) commercial alloys and two master alloys AlSi49 and AlCu55, in a 10 kg capacity ceramic crucible. Optical microscope, transition electron microscope and scanning electron microscope were used to characterize the microstructure and intermetallic phases. Secondary dendrite arm spacing measurements were carried out using an Leica Q-Win(TM) image analyzer. Compression tests were conducted at room temperature using a Zwick universal testing machine. Rockwell F-scale hardness tests were conducted at room temperature using a Zwick HR hardness testing machine. Vickers microhardness tests were conducted using a DUH 202 microhardness testing machine. Findings: It was found that the increase of Cu content to 2 wt% leads to change of the Al+Si eutectic morphology, resulting in a grate increase in the ultimate tensile strength and ductility values compared to the alloys include 1 and 4 wt % of Cu. Based on the X-ray phase analysis was found, that change of Cu content don't influences on the phases composition of investigated alloy. Practical implications: The aim of this work is describe in detail the solidification process in a number of AC AlSi9CuX foundry alloys. In investigated alloys there were identified five phases, which can suggest together with thermal analysis, that in these alloys occur four solidification reactions. Originality/value: The carried out work confirmed the solidification reaction of AC AlSi9CuX foundry alloys and shown influence of Cu content on the microstructure and mechanical properties.