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1

Effect of vacuum conditions on stability and crystallization of cobalt based amorphous alloy

Yazici Ziya Ozgur

Materials Science Poland

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2020

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Vol. 38, No. 1

181--188

EN

The aim of this work was to investigate the effects of moderate vacuum conditions (10 Pa, 1 × 103 Pa and 2 × 104 Pa) on glass forming ability, thermal stability and aging behavior of Co42Cu1Fe20Ta5:5B26:5Si5 amorphous samples in terms of size and distribution of crystalline precipitates. The thinnest parts (300 μm) of the wedge-shaped samples were amorphous for all vacuum conditions, and they had similar compositional, structural and thermal characteristics. However, they represented different microstructural features after heat treatments at 950 K and 1100 K. The same phases precipitated in all samples but the amount and the size of the precipitates increased as the pressure was raised to the normal atmospheric value. The differences in the glass forming ability and the microstructure due to aging are considered to originate from lower thermal characteristics, such as relaxation and reduced glass temperature as well as γ parameter, resulting from the poor vacuum pressure used in the production process. The differences in the microstructures and hardness values caused by heat treatments have been observed.

2

Influence of silver on glass forming ability and mechanical properties of Zr–Cu–Al alloys

Błyskun P., Cieślak G., Kowalczyk M., Latuch J., Kulik T.

Inżynieria Materiałowa

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2015

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Vol. 36, nr 4

154--159

EN

The work focuses on studying the influence of silver content on the glass forming ability and the mechanical properties of the Zr48Cu36Al16 – xAgx alloys (x = 0, 2, 4, ..., 16 at. %). Rods with a diameter of 3 mm were manufactured by the copper mould casting. X-ray diffraction studies (Fig. 1) revealed that samples with 6÷14 at. % of silver content were fully amorphous. Differential scanning calorimetry (Fig. 3) allowed selecting the alloy that possessed the best glass forming ability on the basis of the supercooled liquid region width (ΔTx). The Zr48Cu36Al6Ag10 alloy exhibited ΔTx = 91 K. Mechanical properties of the alloys were characterized by means of Vickers microhardness (Fig. 5) and room temperature compression tests (Fig. 6). The highest value of microhardness was detected for the partially crystalline Zr48Cu36Al16 alloy (791 HV). However, the highest compression strength was measured for the Zr48Cu36Al12Ag6 alloy (σc = 1881 MPa). It should be noticed that a plastic strain was observed in the fully amorphous alloys. On the other hand, partially crystalline samples cracked catastrophically without any observable plastic strain. These studies revealed that the silver content increase resulted in the microhardness and the compression strength decrease. Good mechanical performance and satisfying glass forming ability of the fully amorphous alloys examined at this work seems to be promising set of properties for structural applications. However, the Zr48Cu36Al4Ag12 is the most promising one.

PL

Praca dotyczy określenia wpływu dodatku srebra na zdolność do zeszklenia i właściwości mechaniczne stopów Zr48Cu36Al16 – xAgx (x = 0, 2, 4, ..., 16% at.). Pręty o średnicy 3 mm odlewano do formy miedzianej. Badania dyfrakcyjne promieni rentgenowskich wykazały, że próbki o zawartości srebra 6÷14% at. są w pełni amorficzne. Pozostałe stopy miały zbyt małą zdolność do zeszklenia, aby ulec pełnej amorfizacji w formie o średnicy 3 mm. Różnicowa kalorymetria skaningowa pozwoliła wskazać stopy o największej zdolności do zeszklenia wyznaczanej na podstawie szerokości zakresu cieczy przechłodzonej (ΔTx). Stop Zr48Cu36Al6Ag10 cechował się największą zdolnością do zeszklenia ΔTx = 91 K. Właściwości mechaniczne stopów scharakteryzowano za pomocą pomiarów mikrotwardości i statycznej próby ściskania w temperaturze pokojowej. Największszą mikrotwardość zmierzono dla próbki częściowo krystalicznej Zr48Cu36Al16 (791 HV). Jednak największą wytrzymałość na ściskanie uzyskano dla próbki w pełni amorficznej Zr48Cu36Al12Ag6 (σc = 1881 MPa). Należy podkreślić, że dla wszystkich próbek amorficznych odnotowano pewien zakres odkształcenia plastycznego. Natomiast wszystkie próbki częściowo krystaliczne pękały katastroficznie bez odkształcenia plastycznego. Badania wykazały, że wzrost zawartości srebra powoduje zmniejszenie zarówno mikrotwardości, jak i wytrzymałości na ściskanie, ale w pewnym zakresie (6÷15% at.) wyraźnie poprawia zdolność do zeszklenia. Dobre właściwości mechaniczne i zadowalająca zdolność do zeszklenia stopów w pełni amorficznych, badanych w tej pracy, wydają się obiecującym zestawieniem właściwości w przypadku przyszłych zastosowań konstrukcyjnych. Stop o składzie Zr48Cu36Al4Ag12 okazał się optymalnym kandydatem.

3

The selected manufacturing problems of the bulk metallic glasses

Pilarczyk W.

Selected Engineering Problems

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2013

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nr 4

139--142

EN

In this article selected problems that occur during the manufacture of bulk metallic glasses have been discussed. A number of different techniques to synthesize bulk metallic glasses (BMG) alloys have been developed. These developments have been occurred in different laboratories, for some specific applications or materials. In this paper the analysis of glass transition factors and the associated technological problems have been presented. The observations and gained experience during the preparation of iron-based and zirconium-based bulk metallic glasses prepared by die pressure casting method were the basis for this elaboration.

4

The study of structure and glass forming ability of Zr-based amorphous alloy

Pilarczyk W.

Archives of Materials Science and Engineering

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2013

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Vol. 63, nr 1

19--25

EN

Purpose: This paper tends to present the structure and thermal analysis of selected Zr-based amorphous alloy for welding processes. Design/methodology/approach: The studies were performed on Zr-Cu-Ni-Al system alloy in form of plate. The structure analysis of the studied materials in as-cast state was carried out using XRD method. The thermal properties of the as-cast alloy were examined by DSC and DTA methods. The parameters of GFA included Trg, ΔTx, α, β, γ, δ and S were calculated. Findings: The Zr-based amorphous alloy in form of plate with good GFA was produced by die pressure casting method. The investigation methods revealed that the studied as-cast alloy was amorphous. Although, there is probability of crystallites existence which could not be detected by XRD method. The literature study and calculated GFA parameters indicated that the Zr55Cu30Ni5Al10 alloy exhibits good GFA and thermal stability. It is confirmed that these parameters could be used to determine GFA of tested amorphous alloy for welding processes. This Zr-based BMG could be used as tested material for laser welding process. Research limitations/implications: It is very difficult to obtain a Zr-based BMG with large sizes. Usually, the difficulties of the production of zirconium amorphous alloy are connected with the fact that the constituent elements of the analyzed materials have a high chemical affinity for oxygen, and have different melting points. For this reason, the process of producing BMG in zirconium matrix require the using of additional technology to provide specific conditions for the melting and casting. Practical implications: These obtained values of GFA parameters can suggest that studied alloys are suitable materials for further practical application at welding process. Originality/value: The success formation and investigation of the casted Zr-based BMG. The chemical composition of Zr55Cu30Ni5Al10 alloy was tested first time in our laboratory.

5

Thermal properties of Fe-based bulk metallic glasses

Nowosielski R., Januszka A., Babilas R.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 55, nr 2

349--354

EN

Purpose: The aim of paper is presentation of results bulk metallic glasses thermal properties such as temperatures typical for glassy transition and thermal conductivity. Design/methodology/approach: Investigations were realized for Fe₃₆Co₃₆B_{19.2>/sub>Si_4.8Nb samples with dimension 3 mm in diameter. Bulk test pieces were fabricated by copper mold casting method. Thermal analysis of master alloy (DTA) and samples in as-cast state (DSC) was realized. For amorphous structure confirmation the X-ray diffraction phase analysis (XRD) was realized. Additionally scanning electron microscopy (SEM) micrographs were performed in order to structure analysis. Thermal conductivity was determined by prototype measuring station. Findings: The XRD and SEM analysis confirmed amorphous structure of samples. Broad diffraction “halo” was observed for every testing piece. Fracture morphology is smooth with many “veins” on the surface, which are characteristic for glassy state. DTA analysis confirmed eutectic chemical composition of master alloy. Thermal conductivity measurements proved that both samples have comparable thermal conductivity. Practical implications: The FeCo-based bulk metallic glasses have attracted great interest for a variety application fields for example precision machinery materials, electric applications, structural materials, sporting goods, medical devices. Thermal conductivity is useful and important property for example computer simulation of temperature distribution and glass forming ability calculation. Originality/value: The obtained results confirm the utility of applied investigation methods in the thermal and structure analysis of examined amorphous alloys. Thermal conductivity was determined using the prototype measuring station, which is original issue of the paper. In future, the measuring station will be expanded for samples with different dimensions.}

6

The study of glass forming ability of Fe-based alloy for welding processes

Pilarczyk W.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 52, nr 2

83--90

EN

Purpose: This paper tends to present the thermal analysis and structure of selected Fe-based bulk metallic glasses for welding processes. Design/methodology/approach: The studies were performed on Fe-Co-B-Si-Nb alloy in form of plate and rod. Master alloy ingot with compositions of Fe37.44Co34.56B19.2Si4.8Nb4 was prepared by induction melting of pure Fe, Co, B, Si and Nb elements in argon atmosphere. The investigated material was cast in form of plate with thickness 0.5 mm and rod with diameter 3 mm. The structure analysis of the studied materials in as-cast state was carried out using X-ray diffraction (XRD). The thermal properties: glass transition temperature (Tg), onset crystallization temperature (Tx) and peak crystallization temperature (Tp) of the as-cast alloys were examined by differential scanning calorimetry (DSC) and melting temperature (Tm), liquidus temperature (Tl) by differential thermal analysis (DTA) methods. The parameters of glass forming ability included reduced glass transition temperature (Trg), supercooled liquid region (ΔTx), α, β, y, δ and stability (S) were calculated. Findings: The Fe-based bulk metallic glasses in form of plate and rod with good glass forming ability were produced by die pressure casting method. The investigation methods revealed that the studied as-cast bulk metallic glasses were amorphous. These materials exhibit good glass-forming ability. The calculated GFA parameters indicated that the slightly best glass-forming ability has Fe37.44Co34.56B19.2Si4.8Nb4 alloy in form of rod. It is confirmed that these parameters could be used to determine glass forming ability of tested amorphous alloy for welding processes. Research limitations/implications: It is difficult to obtain a bulk metallic glasses in form of plate and rod with large sizes. Various empirical parameters have been proposed to specify the glass forming ability of bulk metallic glasses. Several GFA indicators have been determined by measuring the characteristic thermal parameters. A few simple criteria were calculated to explain the GFA of tested alloys. Practical implications: These obtained values of GFA parameters can suggest that studied alloys are suitable materials for further practical application at welding process. Originality/value: The success formation and investigation of the casted Fe-based bulk metallic glasses. The chemical composition of Fe37.44Co34.56B19.2Si4.8Nb4 alloy were tested first time.

7

Investigation of the structure and properties of Fe-Co-B-Si-Nb bulk amorphous alloy obtained by pressure die casting method

Pilarczyk W., Nowosielski R., Babilas R., Sakiewicz P., Pilarczyk A.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 55, nr 2

363--367

EN

Purpose: The main aim of this paper is investigation of the microstructure and thermal properties of selected Fe-Co-B-Si-Nb bulk amorphous alloy. Design/methodology/approach: The studies were performed on Fe-Co-B-Si-Nb alloy in form of rods with diameter of ø0=1.5 and ø=2 mm. Master alloy ingot with compositions of Fe37.44Co34.56B19.2Si4.8Nb4 was prepared by induction melting of pure Fe, Co, B, Si and Nb elements in argon atmosphere. The structure analysis of the studied materials in as-cast state was carried out using X-ray diffraction (XRD). The thermal properties: glass transition temperature (Tg), onset crystallization temperature (Tx) and peak crystallization temperature (Tp) of the as-cast alloys were examined by differential scanning calorimetry (DSC) method. The microscopic observation of the fracture morphology of studied amorphous materials in rods form with different diameter was carried out by means of scanning electron microscope (SEM), within different magnification. Findings: The Fe-based bulk metallic glasses in form of rod were successfully produced by die pressure casting method. The investigation revealed that the studied rods are amorphous. These materials exhibit good glass-forming ability. These tested rods with diameter of 1.5 and 2 mm exhibit similar characteristic temperatures (Tg, Tx, Tp). The exothermic peaks describing crystallization process of studied bulk metallic glasses are observed Morphology of cross section rods is changing having contact with copper mould during casting from smooth fracture inside rod to fine narrow dense veins pattern near to rod surface. These rods have smooth surface and metallic luster. The presented fractures are characteristic for metallic glasses. Practical implications: The success of production of studied Fe-based bulk metallic glasses is important for future practical application of those materials as elements of magnetic circuits, sensors and precise current transformers. Originality/value: The success formation and investigation of the casted Fe-based bulk metallic glasses. The chemical composition of Fe37.44Co34.56B19.2Si4.8Nb4 alloy in form of rod were tested first time.

8

Influence of silver on the glass forming ability and mechanical properties in Cu-Zr-Ti-Ag bulk metallic glasses

Latuch J., Błyskun P., Kulik T.

Inżynieria Materiałowa

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2012

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Vol. 33, nr 6

573--575

EN

In this work the influence of silver content on both thermal and mechanical properties in Cu-Zr-Ti-Ag alloys was investigated. Bulk metallic glasses (BMGs) of general composition Cu-Zr-Ti show good glass forming ability (GFA) compared to other Cu-based systems. The addition of silver as fourth element was expected to enhance the GFA even further and improve the mechanical properties. Quaternary Cu48Zr36Ti16 – xAgx (x = 8, 11, 13 at. %) alloys were produced by copper mould casting, manufacturing rod shape samples with the diameter of 3 mm. All manufactured samples were fully amorphous proving the good GFA. The GFA of studied alloys has been investigated on the basis of temperature interval of supercooled liquid region and thermal stability parameters (such as activation energy of crystallization and the crystallization onset temperature). Thermal properties were measured by the differential scanning calorimetry. Mechanical properties of the investigated alloys were determined by means of Vickers microhardness and room temperature compression test. The supercooled liquid region exceeds 40 K for the Cu48Zr36Ti5Ag11 alloy. Vickers microhardess depends on silver content and varies about the value of 550 HV0,05. Compressive strength exceeds 1700 MPa and is slightly lower than that of comparable Cu-based alloys. After static compression tests the fracture surfaces were observed by the scanning electron microscopy. Proofs of significant temperature rises during samples deformation and fracture were found.

PL

Wpływ srebra na zdolność do zeszklenia i właściwości mechaniczne masywnych szkieł metalicznych typu Cu-Zr-Ti-Ag W ramach pracy przeprowadzono badanie wpływu ilości srebra w stopach Cu-Zr-Ti-Ag na właściwości cieplne oraz mechaniczne. Masywne szkła metaliczne (MSM) o ogólnym wzorze Cu-Zr-Ti wykazują dobrą zdolność do zeszklenia w porównaniu z innymi stopami na osnowie miedzi. Dodatek srebra jako czwartego składnika miał za zadanie jeszcze bardziej poprawić zdolność do zeszklenia i poprawić właściwości mechaniczne. Czteroskładnikowe stopy o wzorze Cu48Zr36Ti16 – xAgx (x = 8, 11, 13% at.) wytworzono metodą odlewania pod ciśnieniem do formy miedzianej, uzyskując próbki w kształcie prętów o średnicy 3 mm. Wszystkie wytworzone próbki miały strukturę amorficzną, dowodząc tym samym dobrą zdolność do zeszklenia. Zdolność ta została określona dokładniej na podstawie szerokości temperaturowego zakresu cieczy przechłodzonej oraz parametrów stabilności cieplnej (takie jak energia aktywacji krystalizacji oraz temperatura początku krystalizacji). Właściwości cieplne zmierzono za pomocą różnicowej kalorymetrii skaningowej. Właściwości mechaniczne badanych stopów określono, mierząc mikrotwardość sposobem Vickersa oraz za pomocą statycznej próby ściskania w temperaturze pokojowej. Zakres cieczy przechłodzonej wykazał szerokość przekraczającą 40 K dla stopu Cu48Zr36Ti5Ag11. Mikrotwardość Vickersa zależy od zawartości srebra i waha się wokół wartości 550 HV0,05. Wytrzymałość na ściskanie przekroczyła nieznacznie 1700 MPa, co jest wartością niewiele mniejszą niż otrzymywana dla porównywalnych stopów na osnowie miedzi. Po statycznych próbach ściskania dokonano obserwacji powierzchni pęknięć za pomocą skaningowego mikroskopu elektronowego. Odnaleziono dowody na znaczny wzrost temperatury podczas odkształcenia i pękania próbek.

9

Effect of Cu addition on the GFA, structure and properties of Fe-Co-based alloy

Lesz S., Babilas R., Madej M., Nowosielski R.

Archives of Materials Science and Engineering

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2012

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Vol. 55, nr 2

70-77

EN

Purpose: The aim of the paper was investigation of the effect of Cu addition on GFA (Glass Forming Ability), structure, magnetic and mechanical properties of amorphous Fe-Co-B-Si-Nb alloy. Design/methodology/approach: The following experimental techniques were used: differential thermal analysis (DTA), transmission electron microscopy (TEM) and X-ray diffraction (XRD) method, measurements of magnetic properties (VSM method), Vickers microhardness (HV). Findings: It was shown that when Cu is added to the Fe-Co-based alloy, increase of the GFA and change of the magnetic properties was obtained. Research limitations/implications: The results can give more details to understand the relationship between structure, magnetic and mechanical properties. Thus can be useful for practical application of these alloys. Practical implications: The (Fe36Co36B19Si5Nb4)100-xCux (x=0 and 0.6) metallic glasses due to their excellent soft magnetic properties have shown great industrial value for commercial application. Many products consisting of these kinds of metallic glasses have been widely used, for example anti-theft labels, precision sensor material, and high efficient magnetic transformers in electronic industry. Originality/value: The applied investigation methods are suitable to determine the changes of GFA and structure combined with magnetic and mechanical properties of (Fe36Co36B19Si5Nb4)100-xCux (x=0 and 0.6) metallic glasses

10

Preparation, structure and properties of Fe-based bulk metallic glasses

Nowosielski R., Babilas R.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 40, nr 2

123-130

EN

Purpose: The work presents preparation methods, structure characterization and chosen properties analysis of Fe-based bulk metallic glasses in as-cast state. Design/methodology/approach: The studies were performed on Fe43Co14Ni14B20Si5Nb4 metallic glass in form of rings, plates and rods. The amorphous structure of tested samples was examined by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) methods. The thermal properties of the glassy samples was measured using differential scanning calorimetry (DSC). The soft magnetic properties examination of tested material contained coercive force, initial magnetic permeability and magnetic permeability relaxation measurements. Findings: The XRD and TEM investigations revealed that the studied as-cast samples were amorphous. Broad diffraction halo is typical for metallic amorphous structures that have a large degree of short-range order. The characteristics of the fractured surfaces showed different zones, which might correspond with different amorphous structures of studied materials. The temperature interval of the supercooled liquid region (ÄTx) defined by the difference between Tg and Tx, is as large as 56 K for the rod with diameter of 3 mm. Differences in coercivity and magnetic permeability between samples with different thickness might be resulted by some difference of amorphous structure. Practical implications: The centrifugal casting method and the pressure die casting method are useful to produce bulk amorphous materials in form of rings, plats and rods. Originality/value: The preparation of studied Fe-based bulk metallic glass in form of rings, plates and rods is important for the future progress in research and practical application of that glassy materials.

11

Influence of nickel on structure and hardness of Fe-Co bulk metallic glasses

Nowosielski R., Januszka A.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 38, nr 1

15-23

EN

Purpose: In the present paper, influence of Ni addition on structure and hardness Fe-based bulk metallic glass were investigated. Design/methodology/approach: The studies were performed on Fe36+xCo36-x-yNiyB19.2Si4.8Nb4 ( x= 0;1, y=0;10;15) glassy alloy in a form of rods with diameter up to 5 mm. The tests, carried out to obtain amorphous metallic glasses, were realized with the use pressure die casting method. The system includes a copper mould, high frequency power supply, quartz nozzle and a source of inert gas as argon. The following experimental techniques were used for the test of structure: X-ray diffraction (XRD) phase analysis and scanning electron microscopy (SEM). Microhardness was examined by Vickers diamond testing machine. Findings: The X-ray diffraction revealed that all samples with thickness 2 mm were amorphous. The structural studies revealed that amorphous structure depended on thickness and nickel contents in a preliminary alloy. Research limitations/implications: The relationship between structure and microhardness can be useful for practical application of these alloys. Practical implications: The Fe-based bulk metallic glasses attracted great interest for a variety of application fields, for example structural materials, electric applications, precision machinery materials. These amorphous alloys exhibit high strength, a high elastic strain limit, high fracture toughness, and other useful mechanical properties which are attractive to many engineering applications. Originality/value: The originality of this paper are studies of changes of structure and hardness of Fe36+xCo36-x-yNiyB19.2Si4.8Nb4 ( x= 0;1, y=0;10;15) mainly depending on Ni addition in this alloy.

12

Glass forming ability of binary Ni60+xNb40-x (x=0;1;2) alloys

Nowosielski R., Januszka A., Pilarczyk W.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 42, nr 1-2

73-80

EN

Purpose: This paper presents the investigations results of fabrication and structure tests binary Ni-Nb metallic glasses. Design/methodology/approach: The studies were performed on Ni60+xNb40-x (x=0, 1, 2) alloys in form of ribbon and rods up to 2 mm. For the purpose of fabrication test pieces, melt spinning and pressure die casting methods were used. The main index for determine glass forming ability was thickness of specimens. To the tests of samples structure X-ray diffraction phase analysis (XRD) and scanning electron microscopy (SEM) were used. Owing to good mechanical properties of Ni-based metallic glasses, microhardness of cast rods were examined. Findings: X-ray diffraction and SEM analysis have revealed that samples in form of ribbons were amorphous, while cast rods were crystalline. Practical implications: The relationship between amorphous structure and good mechanical properties could be promising for many engineering application. The Ni-based bulk metallic glasses are newcomers engineering materials which may be applied to a new type pressure sensor exhibiting higher capability and higher sensitivity Originality/value: Paper present quite new type of binary metallic glasses based on Ni. For the sake of alloy simplicity it is possible that this alloys will be used in many applications.

13

Influence of casting parameters on thermal properties of bulk metallic glass Cu48 Zr 36Ag11Ti5

Błyskun P., Latuch J., Kulik T.

Inżynieria Materiałowa

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2010

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Vol. 31, nr 3

670-672

EN

Bulk metallic glasses are sensitive for parameters related to technological process. Thermal stability of metallic glasses and their structure depends on chemical composition and manufacturing conditions. In this work the influence of copper-based bulk metallic glass casting parameters on its thermal properties is studied. A couple of rod-shaped samples were produced by casting method into a copper mold. Structures of samples as well as thermal properties were investigated. Dependence of thermal properties on casting parameters (temperature, pressure) has been determined. A short discussion about probable reason of this dependence is presented. Finally, the parameters that give the opportunity to achieve an optimal thermal properties were selected.

PL

Stosunkowo nowe materiały, jakimi są masywne szkła metaliczne, wykazują dużą czułość na parametry procesu wytwarzania. Stabilność cieplna szkieł metalicznych i ich struktury zależy nie tylko od składu chemicznego, ale także od warunków wytwarzania. W artykule zawarty jest opis wpływu parametrów procesu odlewania masywnego szkła metalicznego na osnowie miedzi na jego właściwości cieplne. Wytworzono serię próbek w zmiennej temperaturze i rożnym ciśnieniu odlewania. Przeprowadzono badania strukturalne oraz badania cieplne wytopionych próbek. Określono zależność właściwości cieplnych od parametrów procesu odlewania. Przedstawiono krotką dyskusję na temat prawdopodobnego źródła tej zależności. Ostatecznie wytypowano parametry, które pozwalają uzyskać szkło o optymalnych właściwościach cieplnych.

14

Search for new metallic glass compositions in NiZrTi base alloys near multicomponent eutectic positions

Dutkiewicz J., Morgiel J., Lityńska-Dobrzyńska L., Maziarz W., Czeppe T., Parra Carillo M., Massalski T. B.

Archives of Metallurgy and Materials

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2006

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Vol. 51, iss. 4

525-531

EN

In the present study several multicomponent alloys based on zirconium and nickel has been investigated. In the alloy containing Ni25Cu25Zr25Ti25 (all compositions in at. %) the position of the eutectic was identified as Ni29.2Cu29.9Zr17Ti24.9 and the melt spun alloy of this composition has shown a better glass forming ability than other alloys, as manifested by ΔT and Trg increase. The four component alloy was modified by manganese addition and in this case the composition of the eutectic was identified at Ti21Zr14Ni27Cu27Mn7. The melt spun alloy has shown slightly better ΔT and Trg than the initial alloy. Second copper rich eutectic was also identified in this system near Ti16Zr14Ni24Cu39Mn7 showing also Trg: = 0.63. Nickel rich alloy of composition Ni60Nb15Zr15Ti10 has shown primary Ni and Ti rich crystals and the eutectic identified at composition Ni48,5Nb21,5-Ti16.5Zr13,5. The eutectic alloy possess higher crystallization temperature (556°C) than the former one (545°C). TEM studies did not allow to find nanocrystals within the ribbon of the latter alloy. The four component eutectic has been modified by silicon addition and the alloy Ni45Nb21Ti16Zr13Si5 has been cast into an iron mould and melt spun. The alloy has been proved amorphous, however small crystallization peaks were found using DSC at 520°C, while the alloy of eutectic composition containing Ni50.3Nb14.4Ti17.3Zr15.1Si2.8 has shown crystallization temperature at 555°C and well pronounced Tg effect. The TEM studies did not allow to find nanocrystalls in the melt spun eutectic alloy, while crystals of size 1-2 nm were observed in the first alloy. Additions of a fifth element Mn to TiNiZnNi alloy and Si to the NiTiZrNb alloy do not clearly improves glass forming ability of the quintenary eutectics as compared to the quaternary ones.

PL

W niniejszej pracy przebadano kilkanaście stopów wieloskładnikowych na osnowie cyrkonu i niklu W stopie zawierajacym Ni25Cu25Zr25Ti25 skład eutektyki został określony jako Ni29.2Cu29.9Zr17Ti24.9 i stop o tym składzie odlany na wirującym walcu wykazał lepszą skłonność do tworzenia szkła posiadając wyższe współczynniki ΔT i Trg. Do eutektycznego stopu czteroskładnikowego dodano mangan. Skład eutektyki został określony jako Ti21Zr14Ni27Cu27Mn7. Po odlaniu na wirującym walcu stop eutektyczny wykazywał wyższe wskazniki ΔT i Trg jak stop odlany pierwotnie. Drugą eutektykę w tym systemie zidentyfikowano przy składzie Ti16Zr14Ni24Cu39Mn7 uzyskując dla taśmy Tg/Tl: = 0.63. Stop bogaty w nikiel o składzie Ni60Nb15Zr15Ti10 wykazywał po odlaniu kryształy pierwotne wzbogacone w Ni i Ti. Określono skład eutektyki jako Ni48,5Nb21,5-Ti16.5Zr13,5. Odlane taśmy stopu o tym składzie wykazują wyższą temperaturę krystalizacji (556°C) jak stop poprzedni (545°C). Badania TEM nie wykazały w stopie eutektycznym obecności nanokryształów w przeciwieństwie do pierwszego stopu. Stop eutektyczny czteroskładnikowy został zmodyfikowany przez dodatek krzemu i odlano na wirującym walcu stop o składzie Ni45Nb21Ti16Zr13Si5, który wykazał strukturę amorficzną podobnie jak czteroskładnikowy, krystalizując przy 520°C. Określono skład eutektyki o składzie Ni50.3Nb14.4Ti17.3Zr15.1Si2.8 która odlana w postaci taśmy wykazała krystalizację przy 555°C i wyraźny efekt Tg. Badania TEM stopu eutektycznego nie wykazały obecności nanokryształów w taśmach w przeciwieństwie do stopu pierwszego. Dodatki piątego pierwiastka nie wykazały wyraźnej poprawy skłonności do tworzenia szkieł w eutektyce piecioskładnikowej w stosunku do stopów czteroskładnikowych.

15

Determination of thermal and mechanical properties of Ni63Cu9Fe8P20 amorphous alloy

Ziewiec K., Kurtyka P.

Archives of Metallurgy and Materials

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2006

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Vol. 51, iss. 2

217-220

EN

Nickel-copper-iron-phosphorus Ni63Cu9Fe8P20 alloy was cast using melt spinning method. The ribbons in as cast state are characterized with use of TEM and X-ray diffraction. Then the ribbons were heated in DTA up to different temperatures and then characterized with use of X-ray diffraction to see the change of the microstructure after heating to elevated temperatures. The melt-spun ribbons in as-cast state were preliminarily compacted in a die and then compressed. The mechanical characteristics of the compacted ribbons at different temperatures were registered.

PL

Stop niklu, miedzi, żelaza i fosforu o składzie Ni63Cu9Fe8P20 odlewano metodą „melt spinning”. Otrzymane taśmy w stanie po odlewaniu były badane przy pomocy transmisyjnego mikroskopu elektronowego (TEM) oraz dyfraktometru rentgenowskiego. Następnie taśmy nagrzewano w różnicowym analizatorze termicznym (DTA) do różnych temperatur a następnie były one ponownie badane przy pomocy dyfraktometru rentgenowskiego. Po odlewaniu metodą „melt spinning” taśmy były wstępnie prasowane w matrycy w celu otrzymania pastylek a następnie poddawane próbie ściskania. Rejestrowano charakterystyki mechaniczne prasowanych taśm przy różnych temperaturach.