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

2013 ◽  
Vol 592-593 ◽  
pp. 639-642 ◽  
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.

scholarly journals MICROSTRUCTURE AND THERMAL STABILITY OF Al-Fe-X ALLOYS

2018 ◽  
Vol 24 (3) ◽  
pp. 223 ◽  
Author(s):  
Andrea Školáková ◽  
Petra Hanusová ◽  
Filip Průša ◽  
Pavel Salvetr ◽  
Pavel Novák ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Melt Spinning ◽  
Hot Extrusion ◽  
Dispersed Particles ◽  
Cast Alloys ◽  
Rapidly Solidified ◽  
Thermal Stability Of ◽  
Melt Spinning Technique ◽  
Extrusion Method

<p>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 Al<sub>13</sub>Fe<sub>4</sub>, Al<sub>13</sub>Cr<sub>2</sub> and Al<sub>5</sub>Cr. 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.    </p>

scholarly journals The Development of Rapidly Solidified Magnesium – Copper Ribbons

2016 ◽  
Vol 61 (2) ◽  
pp. 1083-1088
Author(s):  
M. Pastuszak ◽  
G. Cieślak ◽  
A. Dobkowska ◽  
J. Mizera ◽  
K.J. Kurzydłowski
Keyword(s):  
Corrosion Resistance ◽  
Cooling Rate ◽  
Melt Spinning ◽  
Diffraction Method ◽  
Electrode System ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Copper Addition ◽  
Rapidly Solidified ◽  
Thermal Stability Of

Abstract The aim of the present work was to plan and carry out an experiment consisting of amorphization of industrial magnesium alloy WE 43 (Mg - 4 Y - 3 RE - 0.5 Zr) modified by the copper addition. Investigated alloy modified with 20% of copper was rapidly quenched with the use of melt spinning technique. The effects of cooling rate on the structure and properties of the obtained material were extensively analyzed. The structure and phase analysis of samples were examined using X-ray diffraction method (XRD) while the thermal stability of the samples was determined by differential scanning calorimetry (DSC). Microstructure observations were also conducted. The microhardness tests (HV0.02) and corrosion resistance tests were carried out to investigate the properties of the material. Corrosion resistance measurements were held using a typical three-electrode system. As the result of the research, the effect of cooling rate on microstructure and properties of investigated alloy was determined.

Amorphization of rapidly quenched quasicrystalline Al-transition metal alloys by the addition of Si

1986 ◽  
Vol 1 (3) ◽  
pp. 415-419 ◽  
Author(s):  
R.A. Dunlap ◽  
K. Dini
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Metal Alloys ◽  
Icosahedral Symmetry ◽  
Quench Rate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transition Metal Alloys ◽  
Rapidly Solidified ◽  
Thermal Stability Of

The structure and thermal stability of rapidly solidified Al-Cr-Si, Al-Mn-Si, Al-Fe-Si, Al-Co-Si, and Al-Ni-Si alloys have been investigated using x-ray diffraction and thermal analysis measurements. Each series of alloys shows a region of stoichiometry that yields icosahedral symmetry and a region that yields an amorphous phase. Thermal and structural properties of these alloys are reported as a function of stoichiometry and quench rate.

Hrem Studies of Rapidly Solidified Ni-Fe-Al-B Shape Memory Alloys.

1991 ◽  
Vol 246 ◽  
Author(s):  
R. Pērez ◽  
J. A. Juārez-Islas ◽  
P. Johansson ◽  
M. Wallin ◽  
S. J. Savage
Keyword(s):  
Shape Memory ◽  
Martensite Transformation ◽  
Melt Spinning ◽  
Image Contrast ◽  
X Ray Diffraction ◽  
Recoverable Strain ◽  
X Ray ◽  
Atomic Structures ◽  
Wide Range ◽  
Rapidly Solidified

AbstractA series of (NixFeyAlz)0.9983B0.0017 (where x=58-60, y=13-15 and z=26-28, in at%) alloys have been rapidly solidified by - melt spinning. The ribbons have been characterized by HREM, DSC, X-ray diffraction and recoverable strain measurements. The as-cast alloys exhibit excellent bend ductility (in contrast to B2 type alloys conventionally cast) and a wide range of transformation temperatures: Ms=244-466 K, Mf=200-395K, As=236-427K and Af=262-526K. X-ray diffraction shows the presence of β (NiAl), β′ (NiAl), γ (Ni3Al), γ′ (Ni3A1), Ni and other phases such as Fe3Al, FeAl, FeNi and Al5Fe2. It is the β- β′ diffusionless transformation which is responsible for the shape memory effect. The results obtained by transmission electron microscopy (TEM) show two different types of crystalline grains. In one case, the grains have a high density of twins which are the fingerprints of the martensite transformation. However, other areas in the specimen show crystalline grains with very poor image contrast due to the transformation from β′ -β. There are also sections in the specimens with domains of both crystalline sgrains in coexistance. Both crystalline grains have large amounts of precipitates. In the β′ (NiAl) phase the size of the precipitates range fron lnm to lOnm. In the γ (Ni3Al) phase large precipitates (20nm) can be found. Some of them display pentagonal shapes which resemble the image contrast obtained in the TEM for small icosahedral metallic particles. Experimental evidence is also obtained on different habit or twin planes. HREM images from the twinned areas suggest diferent kinds of atomic structures for the parent and martensite crystalline sections. These results give some insights into the nature of the martensite transformation.

Rapid Solidification Microstructures and Precipitation in AL-Mn Alloys

1983 ◽  
Vol 28 ◽  
Author(s):  
R. J. Schaefer ◽  
D. Shechtman ◽  
F. S. Biancaniello
Keyword(s):  
Rapid Solidification ◽  
Growth Kinetics ◽  
Melt Spinning ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rapidly Solidified ◽  
Solidification Microstructures ◽  
Al Matrix

ABSTRACTRapidly solidified Al containing up to to 15 wt.% Mn was prepared by melt spinning. The alloys were examined by TEM and X-ray diffraction in the as-spun condition and after annealing at 450°C. Four precipitate phases were detected, and their growth kinetics were correlated to subgrain structures in the Al matrix.

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

2011 ◽  
Vol 465 ◽  
pp. 199-202 ◽  
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

Thermal Stability of Rapidly Solidified Alloys of Aluminium with Transition Metals

2006 ◽  
Vol 519-521 ◽  
pp. 389-394 ◽  
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.

A microstructural characterization of Co-Zr type permanent-magnet materials

1991 ◽  
Vol 49 ◽  
pp. 782-783
Author(s):  
K. R. Lawless ◽  
G. C. Hadjipanayis
Keyword(s):  
Melt Spinning ◽  
Microstructural Characterization ◽  
X Ray Diffraction ◽  
Ion Milling ◽  
X Ray ◽  
Heat Treated ◽  
Diffraction Patterns ◽  
Rapidly Solidified ◽  
Hard Magnetic Properties

Considerable interest has been shown recently in the hard magnetic properties of Co-Zr, Co-Zr-B, and Co-Hf-B alloys, but as yet no detailed microstructural studies have been published. The Co-Zr phase diagram seems to be reasonably well known, although the crystal structure of the Co11Zr2 phase is only partially determined. This paper will report on some preliminary studies of rapidly solidified Co-Zr-B-Si and Co-Hf-B-Si alloys and binary Co-Zr alloys.All specimens used in this study were prepared by melt spinning. Specific alloys were heat treated at temperatures from 650 to 900°C. TEM specimens were prepared from ribbon material by ion milling.X-ray diffraction studies of these alloys all showed a characteristic broad peak centered around d = 0.205nm. Although it was obvious that this was a complex peak, attempts to deconvolute it were unsuccessful. SAD patterns revealed that major phases in the alloys were very heavily faulted, thus giving rise to the very confusing X-ray diffraction patterns.

Microstructural analysis for Sn-Bi-Sb-In alloy prepared by rapid solidification

2016 ◽  
Vol 12 (2) ◽  
pp. 4244-4254
Author(s):  
Sara Mosaad Mahlab ◽  
Mustafa Kamal ◽  
Abd El-Raouf Mansour
Keyword(s):  
Electron Microscopy ◽  
Microstructure Evolution ◽  
Melt Spinning ◽  
Vickers Microhardness ◽  
Microstructural Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rapidly Solidified ◽  
Melt Spinning Technique ◽  
Scanning Electron

In the present study, Sn70-X at.% -Bi15 at.% -Sb15 at.%- Inx at.%  alloy ( x= 0, 2, 4, 6),  were prepared by melt spinning technique. Optical microscopy, scanning electron microscopy combined with energy dispersive X-ray analysis (SEM-EDX), X-ray diffraction analysis (XRD), and Vickers microhardness (Hv); were used to characterize the phase transformation and the microstructure evolution. The results contribute to the understanding of the microstructure evolution in alloys of the type prepared by melt spinning technique. This work reports on a comparative study of the rapidly solidified, in order to compare the microhardness and microstructural analysis. 

scholarly journals Microstructural Investigations of Rapidly Solidified Al-Co-Y Alloys

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
B. Avar ◽  
M. Gogebakan ◽  
M. Tarakci ◽  
Y. Gencer ◽  
S. Kerli
Keyword(s):  
Melt Spinning ◽  
Alloy System ◽  
Supercooled Liquid ◽  
Amorphous Structure ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Glass Forming ◽  
Rapidly Solidified

The alloys with different compositions in the Al-rich corner of the Al-Co-Y ternary system were prepared by conventional casting and further processed by melt-spinning technique. The microstructure and the thermal behavior of the alloys were analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and differential thermal analysis (DTA). It was found that only rapidly solidified Al85Co7Y8alloy exhibited the best glass forming ability (GFA) and a fully amorphous structure. Besides, Al85Co13Y2and Al85Co2Y13alloy ribbons were fully crystalline, whereas Al85Co10Y5and Al85Co5Y10alloy ribbons consisted of some crystalline phases within an amorphous matrix. The SEM results showed the same trend that the crystalline phase fraction decreases with the approaching into best glass former. From DSC results, only Al85Co7Y8amorphous alloy exhibited a glass transition temperature (Tg) at 569 K, and its supercooled liquid region (ΔTx=Tx−Tg) was found to be 17 K. Moreover, other calculated GFA parameters for this alloy system were also discussed.

Sign in / Sign up

Export Citation Format

Share Document