MICROSTRUCTURE AND THERMAL STABILITY OF Al-Fe-X ALLOYS

In this work, Al-11Fe, Al-7Fe-4Ni and Al-7Fe-4Cr (in wt. %) alloys were prepared by combination of casting and hot extrusion. Microstructures of as-cast alloys were composed of aluminium matrix with large and coarse intermetallics such as Al13Fe4, Al13Cr2 and Al5Cr. Subsequently, as-cast alloys were rapidly solidified by melt-spinning technique which led to the supersaturation of solid solution alloying elements. These rapidly solidified ribbons were milled and compacted by hot-extrusion method. Hot-extrusion caused that microstructures of all alloys were fine with uniform dispersed particles. Moreover, long-term thermal stability was tested at temperature 300 °C for as-cast and hot-extruded alloys and chromium was found to be the most suitable element for alloying to improve thermal stability.

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Preparation and Characterization of the Soft Magnetic FeCo-based Amorphous Alloy with Enhanced Magnetic Properties and Thermal Stability

MRS Proceedings ◽

10.1557/proc-644-l7.2 ◽

2000 ◽

Vol 644 ◽

Cited By ~ 1

Author(s):

Martin Hollmark ◽

Victor Tkatch ◽

Sergey Khartsev ◽

Alex Grishin

Keyword(s):

Thermal Stability ◽

Magnetic Properties ◽

Melt Spinning ◽

Crystallization Process ◽

Eutectic Reaction ◽

Soft Magnetic ◽

Differential Permeability ◽

Thermal Stability Of ◽

Melt Spinning Technique

AbstractA glassy structure was formed in the Fe40Co40P14B6 alloy by melt-spinning technique. The as-quenched 2-8 mm wide and 15-30 [.proportional]m thick ribbons exhibit good soft magnetic properties: the saturation magnetization of 1.45 T, the coercive force of 4 A/m and maximum differential permeability at 60 Hz of about 90000. The FeCo-based glass crystallizes via eutectic reaction into a mixture of an austenite and a b.c. tetragonal Fe3P-like phase similar to that of the well-known Fe40Ni40P14B6metallic glass, but at temperatures about 60 K higher than the latter. The evaluation of the thermodynamic and kinetic parameters of crystallization process brought us to the conclusion that the improved thermal stability of the Fe40Co40P14B6 glass is caused by the enhanced interfacial nucleus-glass energy.

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Structure and thermal behavior of lead-free solders prepared by rapid solidification of their melt

Soldering & Surface Mount Technology ◽

10.1108/ssmt-10-2016-0027 ◽

2017 ◽

Vol 29 (1) ◽

pp. 49-53 ◽

Cited By ~ 4

Author(s):

Martin Durisin ◽

Alena Pietrikova ◽

Juraj Durisin ◽

Karel Saksl

Keyword(s):

Thermal Stability ◽

Rapid Solidification ◽

Melt Spinning ◽

Lead Free ◽

Content Type ◽

Intermetallic Particles ◽

Lead Free Solders ◽

Practical Implications ◽

Thermal Stability Of ◽

Melt Spinning Technique

Purpose The paper aims to investigate the structure and thermal stability of newly developed lead-free Sn-based alloys which can be used as novel materials in the soldering of electronic components. Design/methodology/approach Rapid solidification was used to prepare the alloys. Findings The results showed that the microstructure of these solders exhibited uniform distribution and small-sized intermetallic compounds. Also, smaller crystalline size can be expected compared to commercially available counterparts. The analyses revealed a uniform and homogenous distribution of the small intermetallic particles of Cu6Sn5 and Ag4Sn in the microstructure of solders. The practical implications mean an improvement in mechanical properties and thermal stability of such solder joints, which is a precondition of low mechanical, thermo-mechanical stresses in their structure. Originality/value The originality lies in the production of these alloys by the melt spinning technique which was not previously used in the electronics industry.

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Structure of Rapidly Solidified Al-Fe-Cr-Ce Alloy

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.465.199 ◽

2011 ◽

Vol 465 ◽

pp. 199-202 ◽

Cited By ~ 1

Author(s):

Alena Michalcová ◽

Dalibor Vojtěch ◽

Pavel Novák ◽

Ivan Procházka ◽

Jakub Čížek ◽

...

Keyword(s):

Electron Microscopy ◽

Thermal Stability ◽

Transmission Electron Microscopy ◽

Positron Annihilation ◽

Melt Spinning ◽

Positron Annihilation Spectroscopy ◽

Transmission Electron ◽

Rapidly Solidified ◽

Thermal Stability Of

An alloy containing Al – 3wt.% Cr – 3wt.% Fe – 0.8wt. % Ce, was prepared by melt spinning. Structure of obtained ribbons was observed by light, scanning and transmission electron microscopy. It was found out that the structure is very fine. Microhardness of cross sectioned ribbons was also measured. Defects in structure were determined by positron annihilation spectroscopy. The thermal stability of the alloy was observed by comparing rapidly solidified ribbons and ribbons annealed at 400°C and at 500°C for 100 h

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Thermal Stability of Rapidly Solidified Alloys of Aluminium with Transition Metals

Materials Science Forum ◽

10.4028/www.scientific.net/msf.519-521.389 ◽

2006 ◽

Vol 519-521 ◽

pp. 389-394 ◽

Cited By ~ 3

Author(s):

Dalibor Vojtěch ◽

Jan Verner ◽

Barbora Bártová ◽

Karel Saksl

Keyword(s):

Thermal Stability ◽

Transition Metals ◽

Solid Solutions ◽

Melt Spinning ◽

Structural Features ◽

High Thermal Stability ◽

Crystalline Phases ◽

Supersaturated Solid Solutions ◽

Rapidly Solidified ◽

Thermal Stability Of

Rapidly solidified (RS) Al-TM (TM = transition metal) alloys are perspective materials from scientific, as well as technological point of view. Generally, they are produced by the melt atomization or by the melt spinning. Subsequent compaction is commonly performed by the hot extrusion. Since transition metals, such as Cr, Fe, Ni, Zr, Ti, Mn and others, have low diffusion coefficients in solid aluminium (lower by several orders of magnitude than those of common alloying elements like Cu, Si, Mg, Zn etc.) the RS Al-TM alloys are characterized by a high thermal stability. In this paper, several RS Al-TM (TM = Cr, Fe, Ti, Mn, Ni) alloys prepared by the melt spinning and melt atomization are compared to commercially available 2xxx, 6xxx and 7xxx wrought alloys. The main structural features of both RS and wrought alloys are described. The RS alloys are characterized by the presence of micro and nano-scale crystalline and/or quasi-crystalline phases and supersaturated solid solutions. The elevated-temperature behaviour is compared for both groups of materials. The thermal stability of the investigated materials is determined by room temperature hardness measurements after various annealing regimes and a high thermal stability of the RS alloys is demonstrated. The microstructural changes and phase transformations occurring in the investigated materials upon heating are described. In the Al-TM alloys, very slow decomposition of the supersaturated solid solutions, precipitation and decomposition of the metastable quasi-crystalline phases occur.

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Long Term Thermal Stability of Silicide Dispersoids in Rapidly Solidified Al-Fe-V-Si and Related Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.217-222.943 ◽

1996 ◽

Vol 217-222 ◽

pp. 943-950

Author(s):

D.M.J. Wilkes ◽

H. Jones ◽

R.W. Gardiner

Keyword(s):

Thermal Stability ◽

Rapidly Solidified ◽

Thermal Stability Of

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Structure and Properties of PM Nano-Crystalline Al-Cr based Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.567-568.197 ◽

2007 ◽

Vol 567-568 ◽

pp. 197-200

Author(s):

Dalibor Vojtěch ◽

Alena Michalcová ◽

Jan Verner ◽

Jan Šerák ◽

František Šimančík ◽

...

Keyword(s):

Thermal Stability ◽

Elevated Temperature ◽

Tensile Tests ◽

Paper Properties ◽

Excellent Thermal Stability ◽

Nano Crystalline ◽

Rapidly Solidified ◽

Thermal Stability Of ◽

Powder Fraction

In the presented paper, properties of Al-Cr-Fe-Ti alloy produced by powder metallurgy (PM) are described. Rapidly solidified powder alloy was prepared by the pressure nitrogen melt atomization. The granulometric powder fraction of less than 45 μm was then hot-extruded. Microstructure of the as-extruded material comprised recrystallized α-Al grains and spheroids of intermetallic phases. Tensile strength of the investigated material was similar to that of a conventional casting Al-Si alloy commonly used in elevated temperature applications. Excellent thermal stability of the PM Al-Cr based material, which much exceeded the elevated temperature casting alloy, was proved by room temperature tensile tests after long-term annealing at elevated temperature. Reasons for the observed thermal stability of the investigated PM alloy are discussed.

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Thermo-Mechanical Processing of Rapidly Solidified 5083 Aluminium Alloy - Structure and Mechanical Properties

Archives of Metallurgy and Materials ◽

10.1515/amm-2015-0028 ◽

2015 ◽

Vol 60 (1) ◽

pp. 177-180 ◽

Cited By ~ 3

Author(s):

T. Tokarski

Keyword(s):

Mechanical Properties ◽

Melt Spinning ◽

Isothermal Annealing ◽

Hot Extrusion ◽

Extrusion Process ◽

Strengthening Effect ◽

Mechanical Processing ◽

Alloy Structure ◽

Rapidly Solidified ◽

Melt Spinning Technique

AbstractAluminium-magnesium 5083 alloy was rapidly solidified by means of melt spinning technique and plastically consolidated during subsequent hot extrusion process. As a result, rods 8 mm in diameter were obtained. Structure of as-extruded material is characterized by ultra-fined grains, which influences on increasement of mechanical properties of the material. The strengthening effect was further enhanced by application of thermo-mechanical treatment consist of cold rolling combined with isothermal annealing. As a result, reduction of grain size from ∼710 nm to ∼270 nm as well as enhancement of yield stress (330 MPa to 420 MPa) and ultimate tensile strength (410 MPa to 460 MPa) were achieved. Based on received results Hall-Petch coefficients (σ0, k) for 5083 RS material were determined.

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Microstructure and Mechanical Properties of Rapidly Solidified Al-Fe-X Alloys

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.592-593.639 ◽

2013 ◽

Vol 592-593 ◽

pp. 639-642 ◽

Cited By ~ 2

Author(s):

Milena Voděrová ◽

Pavel Novák ◽

Ivo Marek ◽

Dalibor Vojtěch

Keyword(s):

Thermal Stability ◽

Melt Spinning ◽

Solidification Rate ◽

Aircraft Industry ◽

X Ray Diffraction ◽

Initial State ◽

Measurement Results ◽

Cast Alloys ◽

Rapidly Solidified

Rapidly solidified aluminium alloys have many interesting properties such as higher thermal stability and strength, when compared with conventional cast alloys. Due to these properties, RS alloys seem to be prospective for using in automotive or aircraft industry. Aim of this work was to compare the differences in microstructure of alloys containing Fe, Ni and Cr which were prepared by different solidification rate. Alloys were prepared by melt spinning, melting with follow-up quenching into the water and by conventional casting with pouring into brass mould. Microstructure of prepared alloys was investigated by scanning electron microscope; phase composition was determined by x-ray diffraction. In this experiment, microhardness was measured in the initial state of all types of alloys; rapidly solidified alloys were also annealed to determine thermal stability by microhardness measurement. Results indicate that higher solidification rate refines the microstructure which is composed of supersaturated solid solution of alloying elements in aluminium and stable and meta-stable intermetallic phases. Hardness of the alloys increases and microstructure refines with solidification rate.

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Rapidly Solidified Melt-spun Bi-Sn Ribbons: Surface Composition Issues

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v11i5.369 ◽

2016 ◽

pp. 3287-3297

Author(s):

Tarek El Ashram ◽

Ana P. Carapeto ◽

Ana M. Botelho do Rego

Keyword(s):

Chemical Composition ◽

Optical Microscopy ◽

Melt Spinning ◽

Surface Composition ◽

Electrochemical Process ◽

Melt Spun ◽

Bismuth Alloy ◽

The One ◽

Rapidly Solidified ◽

Melt Spinning Technique

Tin-bismuth alloy ribbons were produced using melt-spinning technique. The two main surfaces (in contact with the rotating wheel and exposed to the air) were characterized with Optical Microscopy and AFM, revealing that the surface exposed to the air is duller (due to a long-range heterogeneity) than the opposite surface. Also the XPS chemical composition revealed many differences between them both on the corrosion extension and on the total relative amounts of tin and bismuth. For instance, for the specific case of an alloy with a composition Bi-4 wt % Sn, the XPS atomic ratios Sn/Bi are 1.1 and 3.7 for the surface in contact with the rotating wheel and for the one exposed to air, respectively, showing, additionally, that a large segregation of tin at the surface exists (nominal ratio should be 0.073). This segregation was interpreted as the result of the electrochemical process yielding the corrosion products.

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