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1

Effects of B addition on the microstructure and microhardness of melt-spun Al-7075 alloy

Kilicaslan Muhammed Fatih, Elburni Saad Ibrahim, Yilmaz Yasin, Akkaş Mehmet

Advances in Materials Science

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2022

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Vol. 22, nr 2(72)

5--18

EN

Main aim of this study is to examine change of microstructural and the mechanical properties of Al-7075 alloy depending on B content added with different proportions. Rapid solidification process used to produce the alloys was carried out with a single roll melt spinner via a wheel with a rotational speed of 25 m/s. For the microstructural characterization of the alloys, a scanning electron microscope and X-ray diffraction analyzes were used. According to obtained results, it can be said that B addition led to modification of dimensions and shapes of both α−Al and intermetallic phases occurred, it reduced average grain size from 0.45 μm to 0.34 μm in the microstructure. The B addition also led to dramatically increase in microhardness of the Al-7075 alloy. The microhardness of the alloy with 0.4 wt. % B is 0.19 GPa, this is clearly one times higher than that of the alloy without B addition. The microhardness of the alloy with 1 wt. % B is 0.21 GPa, this is also slightly higher than that of the alloy with 0.4 wt. % B.

2

Structural Characterization of Rapidly Solidified Al71Ni24Fe5 Alloy

Młynarek Katarzyna, Czeppe T., Babilas R.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 3

90--95

EN

The influence of rapid solidification from the liquid state on the structure of Al71Ni24Fe5 alloy was studied. The samples were prepared by induction melting (ingots) and high pressure die casting into a copper mold (plates). The structure was examined by X-ray diffraction (XRD), light microscopy and high resolution transmission electron microscopy (HRTEM). The mechanism of crystallization was described on the basis of differential scanning calorimetry (DSC) heating and cooling curves, XRD patterns, isothermal section of Al-Ni-Fe alloys at 850°C and binary phase diagram of Al-Ni alloys. The fragmentation of the structure was observed for rapidly solidified alloy in a form of plates. Additionally, the presence of decagonal quasicrystalline phase D-Al70.83Fe9.83Ni19.34 was confirmed by phase analysis of XRD patterns, Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) of transmission electron microscopy images. The metastable character of D-Al70.83Fe9.83Ni19.34 phase was observed because of the lack of thermal effects on the DSC curves. The article indicates the differences with other research works and bring up to date the knowledge about Al71Ni24Fe5 alloys produced by two different cooling rates.

3

Producing Ultrafine Grain Structure in AZ91 Magnesium Alloy Cast by Rapid Solidification

Szymanek M., Augustyn B., Kapinos D., Boczkal S., Nowak J.

Archives of Metallurgy and Materials

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2014

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Vol. 59, iss. 1

317--321

EN

The paper presents the technological aspect of the process of casting, crushing and plastic consolidation of semi-finished products from magnesium alloy. The aim of this study was to produce by the rapid solidification process a magnesium alloy from the MgAl9Zn1 family in the form of ribbons with ultrafine grain structure. The material cast in the melt spinning device was next crushed and subjected to the operation of cold consolidation and hot extrusion. The paper presents different stages of the process, including initial characterisation of the obtained material.

PL

W artykule przedstawiono aspekt technologiczny procesu odlewania, rozdrabniania i konsolidacji plastycznej otrzymywa- nych półwyrobów ze stopu magnezu. Celem pracy było wytworzenie metodą szybkiej krystalizacji stopu magnezu z układu MgAlOZn1, o ultradrobnoziarnistej strukturze w postaci taśmy. Materiał odlany na stanowisku melt spinning w kolejnym etapie został rozdrobniony i poddany procesowi konsolidacji na zimno i wyciskaniu na gorąco. W artykule zostały przedstawione poszczególne etapy procesu wraz z wstępną charakteryzacją otrzymywanego materiału.

4

D-gun Sprayed Fe-Al Single Particle Solidification

Wołczyński W., Senderowski C., Morgiel J., Garzeł G.

Archives of Metallurgy and Materials

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2014

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Vol. 59, iss. 1

211--220

EN

Some Fe-Al particles less than 50 μm in diameter were deposited onto the steel substrate by means of the D-gun spraying. A solidification mechanism of an individual particle is described. The particle subjected to the description contained nominally 63 at.% Al. The description was preceded by the TEM / SAED analysis of both the Fe-Al coating and Ni-20Cr interlayer. The whole number of the analyzed particles was partially melted during the deposition. The solidification products like: amorphous phase sub-layer, oscillatory sub-layer which contains two types lamellae distributed alternately and typically non-equilibrium phase sub-layer were revealed. In the micro scale, solidification was considered as a process which occurred in two directions: towards the substrate and towards the non-melted particle part. Both solidification processes underwent the positive thermal gradients. The boron addition was localized within the eutectic precipitates pushed and then rejected by the solid/liquid interface of the solidifying non-equilibrium phase. The proposed model is a general one and therefore can be applied to other systems ;description.

PL

Cząstki proszku Fe-Al niniejsze niż 50 μm w średnicy zostały osadzone detonacyjnie na podłożu stalowym. Opisuje się mechanizm krystalizacji pojedynczej cząstki. Cząstki poddane opisowi zawierały nominalnie 63 aL% Al. Opis poprzedzono badaniami struktury metodą TEM / SAED dotyczącymi zarówno powłoki Fe-Al jak i między warstwy Ni-20Cr. Wszystkie analizowane cząstki były częściowo nadtopione podczas osadzania. Zidentyfikowano produkty krystalizacji takie jak: podwarstwę amorficzną, podwarstwę oscylacyjną zawierającą periodycznie ułożone pły tki dwu faz oraz podwarstwę zawierającą fazę typowo nierównowagową. W mikroskali proces wzrostu faz jest analizowany jako zachodzący w dwu kierunkach: w stronę podłoża i w stronę niestopionej części cząstki. Obydwa procesy wzrostu zachodziły w obecności dodatniego gradientu temperatury. Bor dodany do powłoki został zlokalizowany w eutektyce odepchniętej przez front krystalizacji fazy typowo nierównowagowej. Proponowany model ma charakter ogólny i może być zastosowany do opisu innych systemów.

5

The Production of Material with Ultrafine Grain Structure in Al-Zn Alloy in the Process of Rapid Solidification

Szymanek M., Augustyn B., Kapinos D., Boczkal S., Nowak J.

Archives of Foundry Engineering

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2014

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Vol. 14, iss. 2

57--62

EN

In the aluminium alloy family, Al-Zn materials with non-standard chemical composition containing Mg and Cu are a new group of alloys, mainly owing to their high strength properties. Proper choice of alloying elements, and of the method of molten metal treatment and casting enable further shaping of the properties. One of the modern methods to produce materials with submicron structure is a method of Rapid Solidification. The ribbon cast in a melt spinning device is an intermediate product for further plastic working. Using the technique of Rapid Solidification it is not possible to directly produce a solid structural material of the required shape and length. Therefore, the ribbon of an ultrafine grain or nanometric structure must be subjected to the operations of fragmentation, compaction, consolidation and hot extrusion. In this article the authors focussed their attention on the technological aspect of the above mentioned process and described successive stages of the fabrication of an AlZn9Mg2.5Cu1.8 alloy of ultrafinegra in structure designated for further plastic working, which enables making extruded rods or elements shaped by the die forging technology. Studies described in the article were performed under variable parameters determined experimentally in the course of the alloy manufacturing process, including casting by RS and subsequnt fragmentation.

6

Effect of rapid solidification on structure and mechanical properties of Al-6Mn-3Mg alloy

Lobry P., Błaż L., Sugamata M., Kula A.

Archives of Materials Science and Engineering

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2011

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Vol. 49, nr 2

97-102

EN

Purpose: Experiments on rapidly solidified (RS) and industrially manufactured (IM) Al-6Mn-3Mg alloy were performed to test the effect of RS on the structure and mechanical properties of the material. Design/methodology/approach: Annealing of as-extruded RS and IM samples was performed at 500°C in order to test the stability of structural components and related hardness of the materials. Mechanical properties of as-extruded RS and IM materials as well as the samples preliminarily annealed at 500°C / 6 h were tested by compression at 20°C-500°C. Structural investigations were performed using analytical transmission electron microscopy techniques. Findings: The flow stress for RS-samples was found to be about 240 MPa higher at 293 K than that for IM material. However, the difference between the flow stress values observed for RS and IM samples was remarkably reduced at higher deformation temperatures. Annealing at 500°C was found to result in reduction of the RS-material hardness due to the recovery process and slightly marked coarsening of Al6Mn particles. The particles observed in both as extruded and RS-samples annealed 500°C / 7 days were at least 10-times smaller than that for the industrial material. Practical implications: Due to refined structure and the negligible particle coarsening at high annealing temperatures, the products made from RS Al-6Mn-3Mg alloy can be used at high service temperature applications. Originality/value: Hardening of non-heat-treatable Al-6Mn-3Mg alloy is possible due to effective refining of Al6Mn particles using the rapid solidification and adequate consolidation procedure of RS-powders. The highest flow stress was observed for RS samples tested at room temperature. However, increasing deformation temperature was found to result in reduced difference between the flow stress values received for RS and IM materials.

7

Pattern formation in centrifugal rapid solidification of Al-Zn alloys

Tashlykova-Bushkevich I., Kozak C., Shepelevich V.

Przegląd Elektrotechniczny

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2010

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R. 86, nr 7

227-229

EN

The microstructure including layer-by-layer elemental composition of rapidly solidified Al-6.0; 9.4; 15.0 Zn (at %) alloys has been examined. Three distinct types of microstructure are found out in a transverse cross-section of the foils. Nonuniform Zn depth distribution shows depletion of thin (0.02 ěm) surface layers by Zn. The zone at contact foil surface has the highest microhardness value. The effect of Zn content on pattern formation in rapid solidification of the alloys with respect to microhardness on foil transverse cross-section was summarized.

PL

Mikrostruktura stopów Al-6.0; 9.4; 15.0 Zn (w%) otrzymanych w procesie szybkiego zestalania została zbadana włącznie z analizą składu pierwiastkowego warstwa po warstwie. W przekroju poprzecznym folii wyróżniono trzy różne typy mikrostruktur. Nierównomierny rozkład głębokościowy Zn wykazuje zubożenie cienkich (0,02.m) warstw powierzchniowych w Zn. Strefa na powierzchni styku folii charakteryzuje się najwyższą wartością mikrotwardości Omówiono wpływ zawartości Zn na powstawanie struktur krystalicznych w procesie szybkiego krzepnięcia tych stopów w odniesieniu do mikrotwardości na przekroju poprzecznym.

8

High speed twin roll casting of 6016 aluminium alloy strip

Sakaguchi H., Haga T., Watari H., Kumai S.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

495-498

EN

Purpose: of this paper is to clear the possibility of high speed roll casting of aluminium alloy strip. In the body of the automobiles, a sheet of 6016 aluminium alloy is adopted for the outer panel. Therefore, casting of 6016 was tried in this study. Characteristics of roll cast 6016 were investigated. Design/methodology/approach: was a high speed twin roll caster. The high speed twin roll caster was designed to overcome the low castability of the twin roll caster. Findings: are as below. 6016 alloy could be cast into the strip continuously at the speed of 60 m/min. The thickness of the strip was 3.4 mm. The microstructure at as-cast and after T4 heat treatment was shown. The microstructure was very fine. The mechanical properties were investigated by the tensile test and 180 degrees vending test. The as-cast strip could be cold rolled without homogenization to 1 mm. Result of tensile test was tensile strength was 230MPa, 0.2% proof stress was 118MPa and elongation was 33%. 6016 strip of T4 heat treatment could be bent 180 degrees without occurrence of crack at the outer surface or breaking. Research limitations/implications: is the width of the strip was 100 mm. It is necesarry to test twin roll caster equipped wide rolls. Practical implications: are as below. The mechanical properites of the roll-cast 6016 were enough for the sheet metal for the automobile. The low productivity of the twin roller caster could be improved. Originality/value: is that 6016 strip could be cast continuously at speed 60 m/min and this strip had good mechanical properties.

9

High speed twin roll caster for aluminum alloy thin strip

Haga T., Inui H., Sakaguchi H., Watari H., Kumai S.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 24, nr 1

365-371

EN

Purpose: In the present study, effectiveness of a high-speed twin roll caster for recycling aluminum alloy was investigated. Design/methodology/approach: The effects of the high-speed twin roll caster on alleviating the deterioration of mechanical properties by impurities were investigated. Properties of the cast strip were investigated by metallography, a tension test, and a bending test. Findings: A vertical type twin roll caster for strip casting of aluminum alloys was devised. The strip, which was thinner than 3 mm, could be cast at speeds higher than 60 m/min. Features of the twin roll casters are as below. Copper rolls were used and lubricant was not used in order to increase the casting speed. A casting nozzle was used to set the solidification length precisely. Heat transfer between melt and the roll was improved by hydrostatic pressure of the melt. Separating force was very small in order to prevent sticking of the strip to the roll. Low superheat casting was carried out in order to improve microstructure of the strip. In the present study, effectiveness of a high-speed and high-cooling rate twin roll caster of the present study for recycling aluminum alloy was investigated. Fe was added as impurity to 6063 and A356. The roll caster of the present study was useful to decrease the influence of impurity of Fe. Research limitations/implications: A high-speed twin roll caster of vertical type was designed and assembled to cast aluminum alloy thin strip. Originality/value: The results demonstrate that the high-speed twin roll caster can improve the deterioration by impurities.

10

Selection rules for the production of bulk metallic glass precursors for shape memory materials

Kolomytsev V., Pasko A., Sezonenko A.

Archives of Metallurgy and Materials

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2004

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Vol. 49, iss. 4

825-840

EN

The paper is focused on the development of the following technological paths: (metallic melt) › (bulk metallic glass precursor of shape memory material) › (superplastic deformation on heating through the supercooled liquid region) › (crystallization and final microcrystalline material with martensitic transformation in a predetermined temperature range). Main attention is paid to design of multicomponent (Ti,Zr,Hf)A(Co,Ni,Cu,Pd) B alloys with compositions varied around an effective intermetallic compound AB (A:B = 45:55; 50:50; 55:45). One of the challenging problems here is to find a chemical composition window of our multicomponent systems fitting the known empirical rules for a high amorphization ability and keeping the martensitic transformation and good shape memory properties after crystallization.

PL

Artykuł przedstawia rozwój następującej ściezki technologicznej: (ciecz metaliczna) - (masywne szkło metaliczne jako prekursor materiału z pamięcią kształtu) - (nadplastyczne odkształcenie w zakresie cieczy przechłodzonej) - (krystalizacja w określonym zakresie temperatur i uzyskanie końcowego mikrokrystalicznego materiału z przemiana martenzytyczną). Główną uwagę zwrócono na zaplanowanie wieloskładnikowych stopów (Ti, Zr, Hf)A(Co, Ni, Cu, Pd)B o składzie zmieniajacym się w poblizu składu związku międzymetalicznego AB. Jednym z podstawowych problemów jest znalezienie zakresu składów chemicznych dla układów wieloskładnikowych, pasujących do znanych regułempirycznych tworzenia stopów o dużej zdolności do amorfizacji, i równocześnie zachowania przemiany martenzytycznej oraz dobrego efektu pamięci kształtu po krystalizacji.