Wyniki wyszukiwania - BazTech

1

The Effect of Layer Thickness on the Reflectance of a Quasi One-Dimensional Composite Built with Zr55Cu30Ni5Al10 Amorphous Alloy and Epoxy Resin

Garus Sebastian, Sochacki Wojciech

Archives of Metallurgy and Materials

|

2021

|

Vol. 66, iss. 2

503--510

EN

The study examined the impact of the angle of incidence of mechanical waves on various types of quasi one-dimensional superlattice. Binary periodic structure, quasi-periodic distribution of Thue-Morse layers and Severin’s aperiodic multilayer were used. Using the concatenation and recursive rules, the distribution of layers was determined for individual structure types for generation numbers equal to 3, 4 and 5. The structures were selected so that the thickness of the composite was the same for each type of distribution for a given generation number value. Transfer Matrix Method algorithm was used to determine reflectance. The band structure of reflectance has been demonstrated for incidence angles up to 90 degrees at mechanical wave frequencies up to 50 kHz. The existence of wide bands of high reflectance above the acoustic frequencies was demonstrated for the analyzed structures. Increasing the layer thickness caused an inhomogeneous shifts of transmission peaks towards lower frequencies.

2

Phase Transformation Analysis of the Amorphous Mg72Zn24Ca4 Alloy

Lelito J.

Archives of Foundry Engineering

|

2020

|

Vol. 20, iss. 3

21--24

EN

The paper presents research of metallic glass based on a Mg72Zn24Ca4 alloy. Metallic glass was prepared using induction melting and further injection on a spinning copper wheel. The X-ray diffractometer and differential scanning calorimeter (DSC) were used to investigate the phase transformation of the amorphous ribbon. The heat released in the crystallization process, during isothermal annealing, based on the differential scanning calorimeter investigation, was determined to be 166.18 Jg-1. The effect of isothermal annealing temperature on the kinetics of the amorphous alloy crystallization process using differential scanning calorimeter was investigated. For this purpose, two isothermal annealing temperatures were selected. The incubation time decreases as the temperature of the isothermal annealing increases from 300 to 252 seconds. The same relationship is visible in the case of duration of the phase transformation, which also decreases as the temperature of the isothermal annealing increases from 360 to 228 seconds. The obtained results show a significant influence of isothermal annealing temperature on the degree of phase transformation.

3

Effect of Zr and Nb on the Electrical and Magnetic Properties of the Fe-Zr-Nb-B-Cu Alloy

Noh Junghyun, Park Seungyeon, Hwang Haejin, Lim Kyoungmook

Archives of Metallurgy and Materials

|

2019

|

Vol. 64, iss. 3

879--882

EN

The present study, aims to investigate the effect of minor Zr and Nb alloying on soft magnetic and electrical properties of Fe86 (Zrx Nb1-x )7B6 Cu1 (x=1, 0.75, 0.5, 0.25) alloys. The investigated alloys were prepared through the melt spinning process. Within the examined compositional range (Nb up to 5.25 at%, respectively), the soft magnetic properties and electrical resistivity of the alloys continuously increase with increasing Nb content. However increasing the Nb content further decreases such properties. We could confirm the influence of ratio of Zr and Nb on grain growth and crystallization fraction during crystallization by using the soft magnetic properties and electrical properties.

4

The effect of the amorphous content of laser cladding Ni-Nb-Zr/CaF2 on microstructure and properties

Liang X., Cheng Y., Cheng X., Jiang Y., Kulik T., Ferenc J.

Journal of Machine Construction and Maintenance - Problemy Eksploatacji

|

2018

|

no. 4

33--40

EN

Ni-Nb-Zr/CaF2 amorphous coating was prepared on the surface of SA283GRA steel by adopting a high-power laser cladding system. The results show that the Ni-Nb-Zr/CaF2 coating obtained by laser cladding has a good metallurgical bonding with the matrix of SA283GRA and the amorphous phase was obtained. The different amorphous content was obtained with varied laser power. With the increase of laser power, the dilution rate of the coating gradually increases, the amorphous phase content in the cladding coating decreased gradually, and crystallization near the substrate is significant in the laser coating. As the cladding coating is far from the substrate, the content of amorphous phase increases gradually, and the cladding coating has high thermal stability. The hardness of the Ni-Nb-Zr/CaF2 amorphous coating prepared by a laser power of 4 kW is up to the highest value of 890 HV, which is about 4.7 times that of the base material. The electrochemical corrosion results show that the corrosion resistance of the amorphous layer is better than that of the substrate in NaCl solution with 3.5% corrosive medium. The Ni-Nb-Zr/CaF2 laser coating has a relatively strong amorphous forming ability.

PL

Amorficzną powłokę Ni-Nb-Zr/CaF2 otrzymano na powierzchni stali SA283GrA metodą natryskiwania laserowego, z wykorzystaniem laserów dużej mocy. Uzyskane wyniki badań wykazały, że powłoka Ni-Nb-Zr/CaF2 charakteryzuje się dobrą przyczepnością do podłoża stalowego SA283GrA, a faza amorficzna jest otrzymywana w strefie przypowierzchniowej. Wykazano, że moc wyładowania laserowego istotnie wpływa na zawartość fazy amorficznej. Wraz ze wzrostem mocy lasera zawartość fazy amorficznej w strefie przypowierzchniowej zmniejsza się stopniowo, a stopień krystalizacji powłoki w pobliżu podłoża wzrasta. Zawartość fazy amorficznej zwiększa się gradientowo w funkcji odległości od podłoża. Największą twardość powłoki amorficznej Ni-Nb-Zr/CaF2 890 HV uzyskano z wykorzystaniem lasera o mocy 4kW, tj. ≈4,7 razy większą w stosunku do materiału podłoża. Wyniki badań odporności korozyjnej metodą elektrochemiczną wykazały, że w roztworze NaCl z 3,5% odporność na korozję strefy przypowierzchniowej zawierającej fazę amorficzną jest większa niż odporność korozyjna podłoża. Wykazano również, że faza amorficzna Ni-Nb-Zr/CaF2 ma stosunkowo dużą zdolność do formowania się w strefie przypowierzchniowej i charakteryzuje się dużą stabilnością temperaturową.

5

Crystallization of FeSiB Amorphous Ribbons Induced by Laser Interference Irradiation

Kusinski J., Czyż O., Radziszewska A., Morgiel J., Ostrowski R., Strzelec M., Czyż K., Rycyk A.

Archives of Foundry Engineering

|

2018

|

Vol. 18, iss. 2

27--30

EN

Detailed studies on the effects of pulsed laser interference heating on surface characteristics and subsurface microstructure of amorphous Fe80Si11B9 alloy are reported. Laser interference heating, with relatively low pulsed laser energy (90 and 120 mJ), but with a variable number (from 50-500) of consecutive laser pulses permitted to get energy accumulation in heated areas. Such treatment allowed to form two- Dimensional micro-islands of laser-affected material periodically distributed in amorphous matrix. The crystallization process of amorphous FeSiB ribbons was studied by means of scanning and transmission electron microscopy. Detailed microstructural examination showed that the use of laser beam, resulted in development of nanostructure in the heated areas of the amorphous ribbon. The generation of nanocrystalline seed islands created by pulsed laser interference was observed. This key result may evidently give new knowledge concerning the differences in microstructure formed during the conventional and lased induced crystallization the amorphous alloys. Further experiments are needed to clarify the effect of pulsed laser interference crystallization on magnetic properties of these alloys.

6

Infulence of recrystallization on damping properties of alloy Fe75Zr4Ti3B17Cu1

Bocian M., Mech R., Myszka W., Przybylski M.

Zeszyty Naukowe / Wyższa Szkoła Oficerska Wojsk Lądowych im. gen. T. Kościuszki

|

2016

|

Nr 4

123--134

EN

It is expected that damping in amorphous metals change after its recrystallization. For this purpose study of this phenomena was investigated. An alloy Fe75 Z r4Ti3B17Cu1 was manufactured in a very specific conditions to obtain amorphous structure. To confirm structure of the manufactured material basic testing was conducted including XRD, AFM, LFM and SEM with EDS attachment. The study showed that the structure in fact is partially amorphous and partially nanocrystalline. To determine expected change of damping sample in form of rod was tested for bounce height in controlled conditions before and after heat treatment that changed materials structure. Obtained results indicate decrease of damping after heat treatment and therefore confirms initial assumption.

7

Wpływ rekrystalizacji na właściwości tłumiące stopu Fe75Zr4Ti3B17Cu1

Bocian M., Mech R., Myszka W., Przybylski M.

Zeszyty Naukowe Uczelni Jana Wyżykowskiego. Studia z Nauk Technicznych

|

2016

|

Nr 5

65--74

PL

Uważa się, że tłumienie w przypadku metali o strukturze amorficznej powinno ulec zmianie po ich rekrystalizacji. W niniejszej pracy przedstawiono wyniki badań tego zagadnienia. Badania przeprowadzono na stopie Fe75Zr4Ti3B17Cu1 wykonanym w taki sposób, aby otrzymać materiał o strukturze amorficznej. W celu określenia oczekiwanej zmiany w tłumieniu badanego materiału, przeprowadzono badania polegające na pomiarze wysokości odbicia, dla próbki przed obróbką termiczną i po takiej obróbce. Otrzymane rezultaty pokazały, że względne tłumienie próbki uległo zmniejszeniu po poddaniu jej obróbce cieplnej, tym samym potwierdzając wstępne założenia.

EN

It is expected that damping in amorphous metals changes after their recrystallization. For this purpose a study of this phenomena was investigated. A Fe75Zr4Ti3B17Cu1 alloy was manufactured in very specific conditions to obtain amorphous structure. To determine expected change of damping, a sample in form of a rod was tested for bounce height in controlled conditions before and after heat treatment that changed the material structure. The obtained results indicate a decrease of damping after heat treatment and therefore confirm the initial assumption.

8

Structure and properties of amorphous and nanocrystalline Fe78Si11-xB11Yx(x = 0 or 2) alloys produced in a single production step using controlled parameters melt-spinning method

Błoch K.

Journal of Achievements in Materials and Manufacturing Engineering

|

2015

|

Vol. 73, nr 1

5--12

EN

Purpose: The paper presents results of structural and magnetic properties of Fe78Si11B11 and Fe78Si9B11Y2 alloys in the form of ribbons. The effect of addition of yttrium on the structure and magnetic properties was investigated. Design/methodology/approach: The investigated samples were prepared in the form of ribbons using the melt-spinning method. The material structures were investigated using X-ray diffractometry, Mössbauer spectroscopy and scanning electron microscopy. The magnetic properties were studied using using vibrating magnetometer. Findings: Samples were fabricated using rapid cooling at a rotating copper wheel. Images of fractures of investigated samples obtained by decohesion using same magnifications are similar. The distinct vein like structure or the husk structure are not visible thought they are typical of amorphous and nanocrystalline materials with a high degree of internal stress. Mössbauer spectrum is typical as for amorphous materials that are ferromagnetic. It consists of six lines forming a Zemman's sextet. The hyperfine induction field distribution obtained for this sample shows clearly separated two components: low- and high-field. After the introduction of 2% at. Y to the alloy Fe78Si11B11 in place of Si partial crystallization occurred. The shape of the initial magnetization curves is similar and corresponds to materials with low effective anisotropy. Originality/value: The paper presents some researches of the Fe-based bulk amorphous alloys obtained by the melt-spinning method.

9

Structural Defects in the FeCoYB Amorphous Alloys

Błoch K., Nabiałek M., Gondro J., Szota M.

Archives of Metallurgy and Materials

|

2015

|

Vol. 60, iss. 3A

2019--2023

EN

The aim of this work was to determine the nature of the structural defects that have a major influence on the magnetisation process within the investigated alloys. The structure of the alloys in the as-quenched state was investigated by means of X-ray diffractometry. It was confirmed that the samples were amorphous. The magnetisation was measured within magnetic fields ranging from 0 to 2T using a vibrating sample magnetometer (VSM). The investigation of the ‘magnetisation in the area close to ferromagnetic saturation’ showed that, for this class of alloys, the magnetisation process in strong magnetic fields is connected with the following two influences: 1) Firstly, the rotation of the magnetic moments in the vicinity of the defects, which are the sources of the short-range stresses, and, 2) The dumping of the thermally-induced spin waves by the magnetic field. In the case of the Fe₆₃CoY₇B₂₀ alloy, the magnetisation process is connected with both point and linear defects, whereas for the Fe₆₄Co₁₀Y₆B₂₀ alloy, only with linear defects. This suggests that the size of the defects, determining the character of the magnetisation in the vicinity of ferromagnetic saturation, depends on the atomic packing density. On the basis of analysis of the magnetisation curves, the spin wave stiffness parameter (D_sp) was calculated.

PL

Celem pracy było określenie defektów strukturalnych mających decydujący wpływ na proces magnesowania stopów. Strukturę stopów w stanie po zestaleniu badano za pomocą rentgenowskiej analizy dyfrakcyjnej. Stwierdzono, że badane próbki były bezpostaciowe.. Magnetyzację mierzono w silnym polu magnetycznym (0-2 T) przy użyciu magnetometru wibracyjnego (VSM). Badania magnetyzacji w pobliżu ferromagnetycznego nasycenia wykazały, że proces przemagnesowania badanych stopów w silnych polach magnetycznych związany jest z obrotami momentów magnetycznych w pobliżu defektów będących źródłami naprężeń bliskiego zasięgu oraz z tłumieniem przez pole magnetyczne termicznie wzbudzanych fal spinowych. W przypadku stopu Fe,sub>63Co10Y7B20 za proces magnesowania w silnych polach odpowiedzialne są defekty punktowe oraz liniowe, natomiast w stopie Fe64Co10Y6B20 tylko defekty liniowe. Wskazuje to, że wielkość defektów decydujących o charakterze zmian magnetyzacji w pobliżu ferromagnetycznego nasycenia zależy od gęstości upakowania atomów. Na podstawie analizy krzywych namagnesowania wyznaczono parametr sztywności fali spinowej Dsp.

10

Characterization of selected Mg-based amorphous alloy

Nowosielski R., Kiljan A., Guwer A., Babilas R.

Selected Engineering Problems

|

2014

|

nr 5

103--108

EN

This paper describes results of chosen investigations of Mg-based amorphous alloy. The amorphous structure has been verified by X-ray diffraction method, SEM observations and thermal analysis. The investigations have been done on the glassy alloy Mg65Cu25Y10 in the form of plate which was obtained by copper mould pressure casting

11

Właściwości magnetyczne i mikrostruktura kompozytów wytworzonych na bazie amorficznego stopu Fe60Co10Y8Zr1B20 spajanego żywicą epoksydową

Nabiałek M.

Przetwórstwo Tworzyw

|

2014

|

[R.] 20, nr 1 (157)

56--61

PL

W pracy przedstawiono wyniki badań kompozytów wykonanych na bazie stopu amorficznego o składzie chemicznym Fe60Co10Y8Zr1B20 i żywicy epoksydowej. Badane próbki miały kształt walców o takich samych wymiarach i takiej samej zawartości Epidianu 100. Amorficzny stop objętościowy został niskoenergetycznie rozkruszony i rozdzielony na trzy frakcje: 20 - 50 μm, 50 - 100 μm i 100 - 200 μm a następnie zespolony przy użyciu Epidianu 100. W wyniku przeprowadzonych badań mikrostruktury stwierdzono, że kompozyt na bazie metalicznego stopu jest amorficzny. Stwierdzono również, że rozwinięcie powierzchni dla kompozytu złożonego z metalicznych drobin o frakcji 20 - 50 μm było najmniejsze. Mikrotwardość badanych próbek, niezależnie od wielkości metalicznych drobin była porównywalna. Na podstawie analizy badań magnetyzacji w funkcji natężenia pola magnetycznego wykazano, że wartość pola koercji dla badanych kompozytów rośnie wraz z rozkładem wielkości cząstek metalicznych. Pokazano również, że wielkość frakcji ma znikomy wpływ na wartość magnetyzacji nasycenia.

EN

The paper presents the studies of composites, made from amorphous alloy particles with the chemical composition of Fe60Co10Y8Zr1B20 and epoxy resin. The investigated samples had cylindrical shapes of the same size and contained the same weight content of Epidian 100. The volumetric amorphous alloy was low energy-grinded and separated into three fractions: 20 - 50 μm, 50 - 100 μm and 100 - 200 μm. According to the microstructure studies, it was found that the metal-based alloy is amorphous. It was also found, that the development of the surface of the composite, made up of particles of metallic fraction of 20 - 50 microns, was the lowest. The microhardness of the studied samples, regardless of the size of the metallic particles, was comparable. Based on the analysis of the studies of magnetization as a function of magnetic field strength it was shown that the coercivity field value for the analyzed composites increases with increasing fractions of the metal particles. It was also shown that the fraction size has little effect on the value of the saturation magnetization.

12

Laser induced structure transformation in Co70Fe3Mn3.5Mo1.5B11Si11 amorphous alloy

Mudry S. I., Nykyruy Yu.S.

Materials Science Poland

|

2014

|

Vol. 32, No. 1

28--33

EN

Laser induced structure changes in amorphous Co70Fe3Mn3:5Mo1:5B11Si11 alloy have been studied by means of X-ray diffraction and magnetic properties measurements. Both three types of structural relaxations and a starting stage of crystallization process are considered as main characteristics of structure transformation upon laser treatment. Results of investigation of this amorphous alloy at different parameters of laser irradiation have shown that this alloy becomes partly crystalline after irradiation with laser pulse fluence of about 1.8 J/mm2 and pulse duration t = 2 × 10-5 sec. Increasing of laser pulse fluence above 2.0 J/mm2 leads to the destruction of ribbon, due to intensive evaporation.

13

Technology development of magnesium-based bulk amorphous alloys

Babilas R., Lebuda A., Cesarz-Andraczke K., Sakiewicz P., Nowosielski R.

Selected Engineering Problems

|

2013

|

nr 4

9--12

EN

The paper presents some methods for producing bulk metallic glasses. The study was performed on ternary Mg-based alloys. The Mg65Cu25Y10 glassy alloy was prepared in the form of rods by pressure die casting method of molten alloy into water cooled copper mold. The X-ray diffraction investigations revealed that the examined samples obtained in the bulk form were amorphous.

14

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

|

2013

|

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.

15

The surface structural and mechanical properties of the amorphous CO22Y54AL24 ribbon

Bukowska A., Pietrusiewicz P., Zdrodowska K., Szota M.

Advances in Science and Technology. Research Journal

|

2013

|

Vol. 7, nr 19

1--4

EN

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.

16

Symulacja fizyczna w skali laboratoryjnej odlewania amorficznych stopów żelaza

Żak A., Burian W.

Prace Instytutu Metalurgii Żelaza

|

2012

|

T. 64, nr 1

169-174

PL

Stopy amorficzne są nową grupą materiałów charakteryzującą się w zależności od składu chemicznego, wysoką wytrzymałością rzędu 3-4 GPa i twardością około 8-12 MPa. W artykule przedstawiono fizyczne i techniczne podstawy procesu wytwarzania masywnych stopów żelaza o strukturze amorficznej oraz podano wyniki prób odlewania materiałów amorficznych w procesie odlewania ciśnieniowego wykonanych za pomocą laboratoryjnego stanowiska do wytapiania i odlewania znajdującego się w Zespole Technologii i Aplikacji Wyrobów Instytutu Metalurgii Żelaza.

EN

Amorphous alloys make a new class of materials exhibiting high strength up to 3-4 GPa and hardness up to 8-12 MPa. The paper presents physical and technical bases of the process for manufacturing of bulk amorphous Fe-based alloys. Technical assumptions for construction of experimental unit for melting and casting and results of experimental high pressure casting of new amorphous alloys are described. On the basis of the constructional assumptions the laboratory unit for melting and casting of amorphous alloys was built at Product Technology and Application Group in the Institute for Ferrous Metallurgy.

17

Giant magneto-impedance In amorphous metal lic CO-rich alloys and Sandwich structures

Manko D.Yu.

Pomiary, Automatyka, Komputery w Gospodarce i Ochronie Środowiska

|

2010

|

nr 4

5-7

EN

Giant magneto-impedance in sandwich structures based on Co80-xNixB20 amorphous metallic alloys (x=4,6,8,10,12 at.%) is investigated for alternating current with frequency varied from 1 to 3000 kHz at applied magnetic field. The analysis of possibilities of using the comparable thick separator in sandwich structures is fulfilled. Correlation between value of giant magneto-impedance ratio on single amorphous ribbon and sandwich structure creation is revealed.

PL

Przebadano olbrzymi magneto- opór w strukturze wielowarstwowej na amorficznych stopach metali Co80-xNixB20 (x = 4, 6, 8, 10, 12 at.%) dla prądu zmiennego z częstotliwością zmieniającą się od 1 do 3000 kHz przy zastosowaniu pola magnetycznego. Dokonana została analiza możliwości wykorzystania porównywalnego separatora grubości w strukturze wielowarstwowej. Przedstawiono korelację między wartością współczynnika olbrzymiego magneto-oporu na pojedynczej wstędze amorficznej a tworzeniem się struktury wielowarstwowej.

18

Microstructure and magnetic properties of nanocrystalline Fe-based alloys

Hasiak M., Miglierin M., Kaleta J., Zbroszczyk J., Fukunaga H.

Materials Science Poland

|

2008

|

Vol. 26, No. 1

168--172

EN

Microstructure and magnetic properties of nanocrystalline Fe82(Zr4Nb3)B10Cu1 and Fe80(Zr4Mn3)B12Cu1 alloys with different content of the crystalline phase have been investigated. Changes in the microstructure with progressing crystallization were observed by the room temperature Mössbauer spectroscopy. Good soft magnetic properties and frequency characteristics were found in the nanocrystalline Fe82(Zr4Nb3)B10Cu1 and Fe80(Zr4Mn3)B12Cu1 samples with 50-60% of the crystalline alfa-Fe phase.

19

Crystallization of amorphous Fe-Cr-B alloys investigated with high heating rates

Kamasa P, Varga L K, Myśliński P, Rassolov S G, Maksimov V, Idzikowski B

Materials Science Poland

|

2008

|

Vol. 26, No. 4

947--952

EN

Rapid annealing of metallic glasses results in their physical properties different from those stemming from isothermal or non-isothermal annealing with slow heating rates. Differential thermal analysis (DTA) with heating rates up to 2500 K min-1 was applied to investigate amorphous alloys of the composition Fe85-xCrxB15 (x=0, 1, 5) in order to follow the crystallization process. The results have been compared with those obtained with the usual low heating rate processes available from the commercial DSC method. Simultaneously recorded high heating rates magnetic susceptibilities complement the thermal measurements and reveal an interesting phenomenon of suppression of the decomposition of the residual amorphous phase when the heating rates exceed 1250 K min-1, 550 K min-1 and 250 K min-1 for x=0, 1 and 5, respectively. Both, the high heating rate and the Cr addition facilitate the formation of nanostructure which is stable against a further decomposition.

20

Kompozyt amorficzno-ceramiczny na osnowie stopu niklu umocniony Al2O3 wytworzony metodą syntezy mechanicznej i konsolidacji proszku

Oleszak D., Kulik T., Kolesnikov D.

Kompozyty

|

2007

|

R. 7, nr 4

195-199

PL

Podjęto próbę wytworzenia kompozytu metaliczno-ceramicznego, w którym osnową jest amorficzny stop na bazie niklu Ni59Zr20Ti16Si5, a umacniającą fazą ceramiczną - korund. Kompozyt uzyskano poprzez zagęszczanie proszków metodą prasowania izostatycznego. Stopowe proszki amorficzne na bazie niklu wytworzono metodą mechanicznej syntezy. Do tej mieszaniny dodano w końcowej fazie procesu mielenia proszku korundu (20% obj.). Wykorzystano przy tym dwa rodzaje tego proszku: standardowy mikrometryczny (50 žm) oraz nanoproszek (80 nm). Poddana mieleniu mieszanina proszków wyjściowych uległa amorfizacji. Stwierdzono, że dodatek proszku korundu obniża stabilność termiczną stopu amorficznego. Przejawia się to obniżeniem temperatury początku krystalizacji fazy amorficznej. W przypadku proszku mikrometrycznego przesunięcie to jest stosunkowo niewielkie (kilka stopni), natomiast dla nanoproszku sięga 50°C. Związane jest to prawdopodobnie z ułatwionym zarodkowaniem fazy krystalicznej na nanocząstkach korundu. Podczas procesu prasowania izostatycznego (1,5 GPa, 0,5 h, 440 i 480°C) nastąpiła częściowa krystalizacja amorficznej osnowy kompozytu, co potwierdziły badania rentgenowskie i kalorymetryczne. Na podstawie dyfrakcyjnych badań rentgenowskich można stwierdzić, że otrzymane produkty krystalizacji wykazywały nanokrystaliczny charakter, jednakże dokładna ich charakterystyka wymaga przeprowadzenia dalszych badań (TEM), a proces konsolidacji - optymalizacji.

EN

An attempt was made to obtain bulk metallic glasses composite by mechanical alloying followed by powder compaction. Ni-based amorphous matrix was fabricated by milling of a mixture of pure crystalline elements. Two types of Al2O3 powders were added (20 vol. %) as the ceramic phase: micrometer in size (50 žm) and nanopowder (80 nm). Mechanical alloying resulted in a full amorphization of the alloy. The addition of ceramic powder influenced the thermal stability of the amorphous phase. Especially in the case of nanopowders, the crystallization temperature of the first crystallization stage of amorphous phase was decreased by about 50°C. The applied parameters of isostatic pressing (1.5 GPa, 0.5 h, 440 and 480°C) resulted in partial crystallization of the alloy. It was verified by XRD and DSC studies. The quality of the compaction was checked by optical microscopy observations, revealing some micropores.