On the solidification of Al62Cu20Co15Si3 and Al61Cu19.5Co14.5Si5 alloys

1992 ◽  
Vol 7 (10) ◽  
pp. 2713-2723 ◽  
Author(s):  
B. Grushko ◽  
R. Wittmann ◽  
K. Urban
Keyword(s):  
Optical Metallography ◽  
Quasicrystalline Phase ◽  
Solidification Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Decagonal Phase ◽  
Transmission Electron ◽  
Rapidly Solidified ◽  
Dominant Phase ◽  
Elemental Form

The solidification behavior of Al62Cu20Co15Si3 and Al61Cu19.5Co14.5Si5 alloys was studied by means of optical metallography, scanning and transmission electron microscopy, energy-dispersive x-ray analysis, powder x-ray diffraction, and differential thermal analysis. Slowly as well as rapidly cooled ingots of both alloys contained a decagonal quasicrystalline phase as the dominant phase with, additionally, several minor crystalline phases. The structure of the rapidly solidified Si-containing alloys was similar to that of the ternary Al65Cu20Co15 alloy. In the slowly solidified alloys the substitution of 3 at. % Al by Si did not change the basic phase constitution. Si was only partially incorporated in the decagonal phase and a significant quantity of Si was found in elemental form. The increase of Si concentration to 5 at. % resulted in the appearance of new minor phases.

Solidification of Al65Cu20Co15 and Al65Cu15Co20 alloys

1991 ◽  
Vol 6 (12) ◽  
pp. 2629-2636 ◽  
Author(s):  
B. Grushko ◽  
K. Urban
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Quasicrystalline Phase ◽  
Solidification Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Decagonal Phase ◽  
Cscl Type ◽  
Dominant Phase ◽  
Scanning Electron

The solidification behavior of Al65Cu20Co15 and Al65Cu15Co20 alloys was studied by means of scanning electron microscopy, energy-dispersive x-ray analysis, powder x-ray diffraction, and differential thermal analysis. Slowly cooled as well as rapidly cooled ingots of both alloys contained a decagonal quasicrystalline phase as dominant phase with additions of several minor normal-crystalline phases. The decagonal phase was found to solidify in a temperature range limited by two peritectic reactions involving phases of CsCl-type structure. Formation of AlCu and Al2Cu phases was also observed.

On the Mechanical Milling of the AlCuFe Icosahedral Phase with Water

2014 ◽  
Vol 793 ◽  
pp. 23-27
Author(s):  
C. Patiño-Carachure ◽  
J. Luis López-Miranda ◽  
F. de la Rosa ◽  
M. Abatal ◽  
R. Pérez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Milling Time ◽  
Induction Furnace ◽  
Icosahedral Phase ◽  
Quasicrystalline Phase ◽  
X Ray Diffraction ◽  
Cast Sample ◽  
X Ray ◽  
Transmission Electron ◽  
Icosahedral Quasicrystalline

In this investigation the Al64Cu24Fe12 alloy was melted in an induction furnace and solidified under normal casting conditions. The as-cast sample was subject to a heat treatment at 700 oC under argon atmosphere in order to obtain the icosahedral quasicrystalline phase in a monophase region. Subsequently, the icosahedral phase was milled for different times and water added conditions. The pre-alloyed and milled powders were characterized using scanning electron microscopy, X-Ray diffraction, and transmission electron microscopy. The experimental results showed that the icosahedral phase is sensitive to the reaction between water and aluminum of the quasicrystalline alloy to generate hydrogen. As the milling time and the amount of water are increased, the embrittlement reaction of the alloy is accentuated releasing more hydrogen.

Rapidly Solidified Al-6Si-3Cu Alloy

2008 ◽  
Vol 570 ◽  
pp. 103-108 ◽  
Author(s):  
C. Triveño Rios ◽  
Claudemiro Bolfarini ◽  
Walter José Botta Filho ◽  
Claudio Shyinti Kiminami
Keyword(s):  
Rapid Solidification ◽  
X Ray Diffraction ◽  
Type Alloy ◽  
X Ray ◽  
Optical Scanning ◽  
Transmission Electron ◽  
Al2cu Phase ◽  
Solidification Processes ◽  
Dendritic Arm Spacing ◽  
Rapidly Solidified

Rapid solidification processes, RSP, are powerful tools to induce microstructural modifications, which may improve mechanical properties of alloys. In this paper the influence of rapid solidification on the formation of the undesirable brittle intermetallic compounds promoted by Si and Fe in Al-6Si-3Cu (A319-type) alloy have been investigated. The alloy have been casted using both conventional method and water-cooled wedge-copper mould. The microstructures have been evaluated by using a combination of X-ray diffraction, optical, scanning and transmission electron microscopy, and by Vickers microhardness. By increasing the cooling rate the length of the intermetallic β-Al5FeSi phase decreased, accompanying the same tendency of the secondary dendritic arm spacing. These results are accompanied by an increasing in hardness. Moreover, the formation and growth of the Al2Cu phase have been suppressed. These microstructural and hardness changes with the rapid solidification might be attributed to the increased solid solution content of the elements in the Al matrix.

Studying Structure and Magnetic Properties of Armco Steel after Mechanical Treatment

2011 ◽  
Vol 495 ◽  
pp. 216-219
Author(s):  
D. Kokkoris
Keyword(s):  
Electron Microscopy ◽  
Magnetic Properties ◽  
Mechanical Treatment ◽  
Magnetic Hysteresis ◽  
Stress Relief ◽  
Optical Metallography ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Differential Permeability

Results on the correlation of structure and magnetic properties in ARMCO steels after mechanical treatment are reported in this paper. Samples have undergone plastic deformation by means of cold rolling and tensile stress in their as-bought state and after stress-relief process. Minor magnetic hysteresis measurements in 1 Hz have been performed in the as-bought, annealed and plastically deformed samples. X-ray diffraction, optical metallography and transmission electron microscopy have been employed to determine the microstructure of the samples. A clear decreasing monotonic dependence of the maximum differential permeability on applied stress and dislocation density has been observed.

Characterization of ballistically deformed tungsten [100]-, [111]-, and [110]-oriented single crystal penetrators by optical metallography, x-ray diffraction and transmission electron microscopy

2004 ◽  
Vol 19 (12) ◽  
pp. 3451-3462
Author(s):  
R.A. Herring ◽  
W.J. Bruchey ◽  
P.W. Kingman
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Crystal ◽  
Energy Efficient ◽  
Optical Metallography ◽  
Alternative Mechanism ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Wavy Cavity

Single-crystal penetrators of tungsten having orientations of [100], [111], and [110] were ballistically deformed into targets of standard armor material and characterized by optical metallography, x-ray diffraction, and transmission electron microscopy (TEM) methods, which showed significant differences in their deformation mechanisms and microstructures corresponding to their deformation performance as measured by the penetration of the target. The [100] single-crystal penetrator, which produced the most energy efficient deformation, provided a new, alternative mechanism for ballistic deformation by forming small single-crystal blocks, defined by {100} oriented cracks, which rotated during extrusion from the interior to the side of the penetrator while maintaining their single crystal integrity. The [111] single-crystal penetrator transferred mass along allowed, high-angle deformation planes to the penetrator’s side where a buildup of mass mushroomed the tip until the built-up mass let go along the sides of the penetrator, creating a wavy cavity. The [110] penetrator, which produced the least energy-efficient deformation, has only two allowed deformation planes, cracked and rotated to invoke other deformation planes.

scholarly journals Synthesis and stability of quasicrystalline phase in Al-Cu-Fe-Si mechanically alloyed powders

2021 ◽  
Vol 56 (18) ◽  
pp. 11071-11082
Author(s):  
Mikołaj Mitka ◽  
Anna Góral ◽  
Lidia Lityńska-Dobrzyńska
Keyword(s):  
Phase Formation ◽  
Icosahedral Phase ◽  
Quasicrystalline Phase ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
X Ray ◽  
Transmission Electron ◽  
20 Nm ◽  
Si Addition ◽  
Thermal Stability Of

AbstractThe effect of Si addition on a quasicrystalline phase formation in Al-Cu-Fe-Si alloys prepared by mechanical alloying has been investigated using X-ray diffraction and scanning and transmission electron microscopy. Two compositions containing 10 at.% of Si were selected to verify the influence of the e/a ratio on a sequence of phase formation during milling: Al58.5Cu18Fe13.5Si10 (e/a = 1.98) and Al53.5Cu19.5Fe17Si10 (e/a = 1.75). A quasicrystalline icosahedral phase (i-phase) was found in both alloys after 10 h of milling in the form of nano-quasicrystallites with the size of 10–20 nm. Addition of Si stabilized the quasicrystalline phase being dominant after prolonged milling time, contrary to the reference ternary Al65Cu20Fe15 powder, which apart of the quasicrystalline phase contained the cubic β-Al(Cu, Fe) phase. Thermal stability of the quasicrystalline phase in the powders milled for 10 h was examined after annealing at 800 °C for 4 h. The i-phase was preserved partially in Al53.5Cu19.5Fe17Si10 and reference Al65Cu20Fe15 powders (both with a ratio e/a = 1.75), which coexisted with β-Al(Cu, Fe) and Al13Fe4 phase or α-Al55Si7Cu25.5Fe12 and Al2Fe3Si3 phases in Al65Cu20Fe15 and Al53.5Cu19.5Fe17Si10, respectively. For the Al58.5Cu18Fe13.5Si10 powders (e/a = 1.98), the annealing led to complete transformation of the i-phase to the cubic α-Al55Si7Cu25.5Fe12.5 approximant, forming crystallites with a size of 100–300 nm. Graphical abstract

Microstructures of Fe-Pd Alloy Ribbons Subjected to Rapidly Solidified Melt Spinning

2013 ◽  
Vol 738-739 ◽  
pp. 431-435
Author(s):  
Yoichi Kishi ◽  
Takeshi Kubota ◽  
Zenjiro Yajima ◽  
Teiko Okazaki ◽  
Yasubumi Furuya ◽  
...  
Keyword(s):  
Pole Figure ◽  
Melt Spinning ◽  
Room Temperature ◽  
Parent Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Oriented Texture ◽  
Pd Alloy ◽  
Rapidly Solidified

Microstructures of the Fe-29.6at%Pd alloy ribbons were observed with an X-ray diffractometer and a transmission electron microscope. The X-ray diffraction profiles at room temperature showed that the ribbon consists of FCT martensitic phase and FCC parent phase. Moreover, the ribbon exhibits a strongly 200-oriented texture analyzing with pole figure measurements. TEM bright field images for the cross section of the ribbon showed high-density striation in the FCT martensite variants. Twin-related two sets of reflections were observed in the SAED patterns taken of the FCT martensite variants. FCT was nearly parallel to the thickness direction according to the analysis of the SAED patterns. This result corresponds to the pole figure measurements.

Ni-Mo-Cr-B Alloys: Corrosion Resistant Amorphous Hardfacing Coatings

1983 ◽  
Vol 28 ◽  
Author(s):  
S. K. Das ◽  
E. M. Norin ◽  
R. L. Bye
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Plasma Spraying ◽  
Corrosion And Wear ◽  
X Ray Diffraction ◽  
Corrosion Resistant ◽  
X Ray ◽  
Amorphous Ribbons ◽  
Transmission Electron ◽  
Rapidly Solidified

ABSTRACTA series of rapidly solidified Ni-Mo-Cr-B alloys have been investigated for possible application as corrosion resistant hardfacing coatings. As-cast amorphous ribbons were pulverized to powder, which was subsequently applied to a substrate by plasma spraying. The coatings are substantially amorphous, as revealed by x-ray diffraction and transmission electron microscopy. They exhibit ∼95% of theoretical density and exhibit good corrosion and wear resistances, superior to those of many commercially available hardfacing coatings.

Metastable ordered austenite in rapidly solidified Fe-Al-C alloys

1989 ◽  
Vol 47 ◽  
pp. 516-517
Author(s):  
J. A. Sarreal
Keyword(s):  
Rapid Solidification ◽  
Melt Spinning ◽  
X Ray Diffraction ◽  
Austenitic Phase ◽  
X Ray ◽  
Transmission Electron ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
Equilibrium Phases ◽  
Rapidly Solidified

Conventionally cast Fe-Al-C alloys are extremely brittle containing combinations of ferrite, carbide and other phases. Rapid solidification has the potential of altering the microstructure to subsequently change the resulting mechanical properties. An apparent conflict exist concerning the effect of rapid solidification on the resulting microstructure of these alloys. Inoue and co-workers, using transmission electron microscopy (TEM) and electron diffraction analyses, reported the presence of several non-equilibrium phases including austenite (fcc - γ) and ordered austenite (Ll2-γ') structures on alloys containing 1.7 to 2.1 C and 6 to 12 Al in weight % (w/o) on melt spun ribbons 30 μm in thickness. Han and Choo, using x-ray diffraction analysis on 30-48 μm thick melt spun ribbons concluded that this ordered fee phase is rather an austenitic phase in which phase decomposition accompanied by sideband phenomenon had occured.Single roller melt spinning technique was used to make ribbons 35-70 μm thick and 0.5-5 mm wide. X-ray diffration analysis showed single phase austenite for samples 2-6 w/o AI and 2 w/o C. Samples with 8-10 w/o AI and 2 w/o C also showed several superlattice lines in addition to the fundamental fcc peaks.

scholarly journals Structural Characterization of Al65Cu20Fe15 Melt-Spun Alloy by X-ray, Neutron Diffraction, High-Resolution Electron Microscopy and Mössbauer Spectroscopy

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 54
Author(s):  
Rafał Babilas ◽  
Katarzyna Młynarek ◽  
Wojciech Łoński ◽  
Dariusz Łukowiec ◽  
Mariola Kądziołka-Gaweł ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Neutron Diffraction ◽  
Quasicrystalline Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Icosahedral Quasicrystalline Phase ◽  
Icosahedral Quasicrystalline

The aim of the work was to characterize the structure of Al65Cu20Fe15 alloy obtained with the use of conventional casting and rapid solidification-melt-spinning technology. Based on the literature data, the possibility of an icosahedral quasicrystalline phase forming in the Al-Cu-Fe was verified. Structure analysis was performed based on the results of X-ray diffraction, neutron diffraction, 57Fe Mössbauer and transmission electron microscopy. Studies using differential scanning calorimetry were carried out to describe the crystallization mechanism. Additionally, electrochemical tests were performed in order to characterize the influence of the structure and cooling rate on the corrosion resistance. On the basis of the structural studies, the formation of a metastable icosahedral phase and partial amorphous state of ribbon structure were demonstrated. The possibility of the formation of icosahedral quasicrystalline phase I-AlCuFe together with the crystalline phases was indicated by X-ray diffraction (XRD), neutron diffraction (ND) patterns, Mössbauer spectroscopy, high-resolution transmission electron microscopy (HRTEM) observations and differential scanning calorimetry (DSC) curves. The beneficial effect of the application of rapid solidification on the corrosive properties was also confirmed.

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