Microstructure of Rapidly Solidified Melt-Spun Ribbon in AlCoCrFeNi2.1 Eutectic High-Entropy Alloys

2016 ◽  
Vol 879 ◽  
pp. 1350-1354 ◽  
Author(s):  
Takeshi Nagase ◽  
Mamoru Takemura ◽  
Mitsuaki Matsumuro
Keyword(s):  
Grain Boundary ◽  
Rapid Solidification ◽  
Crystalline Structure ◽  
Xrd Analysis ◽  
Solidification Structure ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
Rapidly Solidified

The microstructure of rapidly solidified melt-spun ribbon in AlCoCrFeNi2.1 eutectic high entropy alloys (EHEAs) was investigated for clarifying the effect of rapid solidification on the constituent phases and microstructure of specimens formed through solidification. XRD analysis indicates that the melt-spun ribbons were composed of a mixture of fcc and bcc phases. The rapidly solidified melt-spun ribbon shows a fine poly-crystalline structure with fcc matrix phase and crystalline precipitates in the grain boundary, indicating that the solidification structure in the melt-spun ribbon was significantly different from that obtained by conventional casting processes.

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.

Large reversible magnetic entropy change in rapidly solidified Ni0.895Cr0.105MnGe1.05 melt-spun ribbons

2018 ◽  
Vol 97 ◽  
pp. 89-94 ◽  
Author(s):  
Anil Aryal ◽  
Abdiel Quetz ◽  
C.F. Sánchez-Valdés ◽  
P.J. Ibarra-Gaytán ◽  
Sudip Pandey ◽  
...  
Keyword(s):  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
Rapidly Solidified

On the controllability of phase formation in rapid solidification of high entropy alloys

2018 ◽  
Vol 748 ◽  
pp. 679-686 ◽  
Author(s):  
Mehdi Jafary-Zadeh ◽  
Zachary H. Aitken ◽  
Rouhollah Tavakoli ◽  
Yong-Wei Zhang
Keyword(s):  
Rapid Solidification ◽  
Phase Formation ◽  
High Entropy Alloys ◽  
High Entropy

scholarly journals Structure and mechanical properties of composite amorphous-crystalline Al-based materials synthesized by high pressure torsion.

2020 ◽  
Vol 11 (3-2020) ◽  
pp. 156-162
Author(s):  
K. A. Svyrydova ◽  
◽  
V. V. Burkovetskii ◽  
T. V. Tsvetkov ◽  
V. I. Parfeniy ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Crystalline Structure ◽  
High Pressure Torsion ◽  
Structural Studies ◽  
Nanocomposite Structure ◽  
Amorphous Ribbons ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
Deformation Level

The results of the structural studies and hardness measurements of bi-and three-layer samples obtained by high pressure torsion of melt-spun ribbons of Al-based alloys with amorphous and crystalline structures have been presented. It has been established that straining of amorphous ribbons results in formation of nanocomposite structure while that refinement of crystalline structure and increase of microstrains takes place in crystalline ribbon. It has been found that the hardness of the consolidated samples increases with the increase of the deformation level up to 4,7 GPa.

Limits of grain boundary engineering in nanocrystalline Nd-Fe-B melt-spun ribbons

2020 ◽  
Vol 264 ◽  
pp. 127338 ◽  
Author(s):  
Marko Soderžnik ◽  
Bojan Ambrožič ◽  
Kristina Žagar Soderžnik ◽  
Matic Korent
Keyword(s):  
Grain Boundary ◽  
Grain Boundary Engineering ◽  
Melt Spun ◽  
Melt Spun Ribbons

scholarly journals Enhanced magnetocaloric effect in rapidly solidified HoNi2 melt-spun ribbons

2019 ◽  
Vol 774 ◽  
pp. 700-705 ◽  
Author(s):  
J.L. Sánchez Llamazares ◽  
P. Ibarra-Gaytán ◽  
C.F. Sánchez-Valdés ◽  
Pablo Álvarez-Alonso ◽  
R. Varga
Keyword(s):  
Magnetocaloric Effect ◽  
Melt Spun ◽  
Melt Spun Ribbons ◽  
Rapidly Solidified

scholarly journals Microstructure and Microhardness Evolutions of High Fe Containing Near-Eutectic Al-Si Rapidly Solidified Alloy

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Emad M. Ahmed ◽  
M. R. Ebrahim
Keyword(s):  
Length Distribution ◽  
Spherical Shape ◽  
Solidification Process ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fe Content ◽  
Melt Spun ◽  
Solid Solubility Extension ◽  
Rapidly Solidified

Al-11 wt.% Si-11 wt.% Fe (11.29 at.% Si-5.6 at.% Fe) melt was rapidly solidified into ribbons and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and microhardness technique. The Rietveld X-ray diffraction analysis was applied successfully to analyze microstructure and phase precipitations. On the basis of the aluminum peak shifts measured in the XRD scans, a solid solubility extension value of 1 at.% Si in α-Al was determined. SEM investigations confirmed presence of a spherical shape α-phase particles in addition to needle and spherical shape β-phase particles with contents of 1.1 wt.% and 10.1 wt.% as deduced by XRD analysis. During prolonged annealing process at 350°C/25 h, α-phase disappeared, β-phase content increased to 30 wt.%, and Si presence becomes more evident as deduced by XRD analysis. EDS analysis confirmed that these β particles observed in the as-melt spun alloy are of lower Fe content comparing to those usually observed in the as-cast counter-part alloy. Besides, the length distribution of needle shape β-particles has been shortened to be diverse from 1 to 5 μm. The as-melt spun ribbons exhibited enhancement of hardness to 277 HV and further increased during heat treatment (150°C/12 h) to 450 HV. This improvement of microstructure and hardness are the influence of microstructural refinement and modification obtained during the rapid solidification process.

Preparation of Anisotropic Nd-Lean Nd-Fe-B Magnets with Improved Coercivity

2017 ◽  
Vol 898 ◽  
pp. 1675-1680
Author(s):  
Qian Shen ◽  
Yi Long Ma ◽  
Xue Guo Yin ◽  
Tao Zhou
Keyword(s):  
Magnetic Properties ◽  
Grain Boundary ◽  
Grain Growth ◽  
The Other ◽  
Zn Diffusion ◽  
Energy Product ◽  
Initial Stage ◽  
The Press ◽  
Melt Spun ◽  
Melt Spun Ribbons

Anisotropic bulk nanocrystal Nd-lean Nd-Fe-B magnets were prepared by hot-pressing the mixture of Nd11.5Fe81.5Nb1B6 melt-spun ribbons and pure Zn powder and subsequent hot-deforming. The effects of deformation on the magnetic properties and microstructure were also studied. The magnetic properties increased significantly for hot-deformed (HD) samples due to the formation of good c-axis texture with increasing deformation. The remanence Mr and maximal energy product (BH)m increased and reached their maximal values at 65% deformation due to the increasing orientation. On the other hand, the grains increased and were elongated normal to the press direction gradually with increasing deformation. The variation trend was similar to that of traditional Nd-Fe-B magnets. However, there was an obvious improvement for coercivity in the initial stage of hot-deformation resulting from the adequate Zn diffusion into grain-boundary. When the deformation was larger than 65%, the magnetic properties were deteriorated due to abnormal grain growth. In order to improve further the coercivity Hci, the samples with Dy addition were prepared. The coercivity of 12300 Oe could be obtained for anisotropic bulk Nd9.5Dy2Fe81.5Nb1B6.

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