Hydrogen Storage, Microstructure and Mechanical Properties of Strained Mg65Ni20Cu5Y10 Metallic Glass

2012 ◽  
Vol 729 ◽  
pp. 74-79
Author(s):  
Ádám Révész ◽  
Ágnes Kis-Tóth ◽  
Péter Szommer ◽  
Tony Spassov
Keyword(s):  
High Pressure ◽  
Metallic Glass ◽  
Shear Deformation ◽  
High Pressure Torsion ◽  
Hydrogen Uptake ◽  
X Ray Diffraction ◽  
X Ray ◽  
Melt Spun ◽  
Lower Temperature ◽  
Scanning Electron

Melt-spun amorphous Mg65Ni20Cu5Y10metallic glass compacts were subjected to severe shear deformation by high-pressure torsion. High-resolution X-ray diffraction analysis and scanning electron microscopy revealed that high-pressure torsion resulted in a deformation dependent microstructure. Nanoindentation measurements indicated that the heavy shear deformation yields an increase in hardness. High-pressure calorimetry measurements revealed that hydrogen uptake in the fully amorphous alloy occurs at a significantly lower temperature compared to the fully crystallized state, while the amount of absorbed hydrogen increased considerably after shear strain due to the formation of Mg2Ni crystals.

Volume changes in Vitreloy bulk metallic glass during room temperature high-pressure torsion

2008 ◽  
Vol 23 (12) ◽  
pp. 3409-3414 ◽  
Author(s):  
Zsolt Kovács ◽  
Erhard Schafler ◽  
Ádám Révész
Keyword(s):  
High Pressure ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Volume Changes ◽  
X Ray ◽  
Dimensional Mapping

Commercial Zr44Ti11Cu10Ni10Be25 bulk metallic glass (Vitreloy 1b) disk was subjected to extreme plastic deformation by high-pressure torsion at room temperature. Two-dimensional mapping by high-intensity synchrotron x-ray diffraction in the plane of the shear deformation reveals no evidence of nanocrystallization; however, average effective volume changes as a function of the deformation can be evaluated.

scholarly journals Crystallization of Cu60Zr20Ti20 bulk metallic glass by high pressure torsion

2019 ◽  
Vol 58 (1) ◽  
pp. 304-312
Author(s):  
Ádám Révész ◽  
András Horváth ◽  
Gábor Ribárik ◽  
Erhard Schafler ◽  
David J. Browne ◽  
...  
Keyword(s):  
High Pressure ◽  
Metallic Glass ◽  
Crystallite Size ◽  
Bulk Metallic Glass ◽  
High Pressure Torsion ◽  
Average Crystallite Size ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Microstructural Parameters ◽  
Profile Fitting

Abstract Bulk metallic glass of Cu60Zr20Ti20 composition has been synthesized by copper mold casting. Slices of the as-cast glass has been subjected to severe plastic deformation by high-pressure torsion for different whole turns. The microstructure and the thermal behavior of the deformed disks have been investigated by X-ray diffraction and differential scanning calorimetry. It was confirmed that the initial compression preceding the high pressure torsion induces crystallized structure, which shows only minor further changes upon the severe plastic shear deformation achieved by twisting the sample. The X-ray line profiles have been evaluated by the Convolutional Whole Profile Fitting algorithm in order to determine the evolution of the microstructural parameters, such as the median and variance of the crystallite size distribution, average crystallite size and dislocation density as a function of the number of revolutions. Hardness measurements by nanoindentation have also been carried out on the as-cast alloys and the deformed disks.

Surface oxides and their effect on the oxidation behavior of amorphous and nanoquasicrystalline Zr–Pd and Zr–Pt alloys

2006 ◽  
Vol 21 (3) ◽  
pp. 639-646 ◽  
Author(s):  
K. Mondal ◽  
U.K. Chatterjee ◽  
B.S. Murty
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Oxidation Behavior ◽  
Amorphous Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Oxides ◽  
Melt Spun ◽  
The Difference ◽  
Scanning Electron

The oxidation behavior of melt-spun Zr75Pd25 and Zr80Pt20 alloys with nanoquasicrystalline phase embedded in amorphous matrix has been studied isothermally as well as nonisothermally in static air. The nature of oxides formed during oxidation has been studied by x-ray diffraction and scanning electron microscopy, and a transition in the structure of the oxides has been shown as one of the primary reasons for the difference in the oxidation behavior of the alloys.

The Research on High Pressure Sintering of Mixed Powder γ-Si3N4 and α-Si3N4

2011 ◽  
Vol 284-286 ◽  
pp. 1397-1400
Author(s):  
Huai Yao ◽  
Yong Zhi Wang ◽  
Bo Xu
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Cross Sections ◽  
X Ray Diffraction ◽  
Mixed Powder ◽  
Sintered Ceramic ◽  
X Ray ◽  
Ceramic Samples ◽  
High Pressure Sintering ◽  
Scanning Electron

The high pressure and high temperature sintering of α-Si3N4 and γ-Si3N4 with Y2O3-Al2O3-La2O3 as additives were studied under pressures of 5.4 GPa and temperatures of 1420-1770 K. The effects of sintering temperatures and pressures on properties of sintered ceramic samples were investigated with X-ray diffraction and scanning electron microscopy. The results show that γ-Si3N4 and α-Si3N4 is transformed to β-Si3N4 completely. The highest relative densities and Vickers hardness (HV) of sintered samples are 98.71 and 21.76GPa, respectively. The sintered samples were composed of elongated β-Si3N4 rod crystals with disordered orientation and had intergranular interlocks and uniform and compact microstructure. Pulled out crystal grains on the fractured cross sections were obviously observed by SEM.

Nucleation and growth in bulk metallic glass under high pressure investigated using in situ x-ray diffraction

2003 ◽  
Vol 83 (25) ◽  
pp. 5202-5204 ◽  
Author(s):  
W. H. Wang ◽  
P. Wen ◽  
D. Q. Zhao ◽  
M. X. Pan ◽  
T. Okada ◽  
...  
Keyword(s):  
High Pressure ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Nucleation And Growth ◽  
X Ray Diffraction ◽  
X Ray

Study of Alloys IrxRe1-x (x = 0.65, 0.75 and 0.85)

2013 ◽  
Vol 203-204 ◽  
pp. 55-58 ◽  
Author(s):  
Anton Panchenko ◽  
Tatyana Dyachkova ◽  
Sergey Gromilov ◽  
Yuriy Zaynulin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Ir-Re alloys were synthesized from nanocrystalline iridium and rhenium powders under high pressure (4 GPa) und temperature (2000° C). They were characterized using powder X-ray diffraction and scanning electron microscopy.

scholarly journals Effect of the High-Pressure Torsion (HPT) and Subsequent Isothermal Annealing on the Phase Transformation in Biomedical Ti15Mo Alloy

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1194 ◽  
Author(s):  
Kristína Bartha ◽  
Josef Stráský ◽  
Anna Veverková ◽  
Pere Barriobero-Vila ◽  
František Lukáč ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Phase Evolution ◽  
High Energy ◽  
Phase Precipitation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solution Treated ◽  
Α Phase ◽  
Element Partitioning

Ti15Mo metastable beta Ti alloy was solution treated and subsequently deformed by high-pressure torsion (HPT). HPT-deformed and benchmark non-deformed solution-treated materials were annealed at 400 °C and 500 °C in order to investigate the effect of UFG microstructure on the α-phase precipitation. Phase evolution was examined using laboratory X-ray diffraction (XRD) and by high-energy synchrotron X-ray diffraction (HEXRD), which provided more accurate measurements. Microstructure was observed by scanning electron microscopy (SEM) and microhardness was measured for all conditions. HPT deformation was found to significantly enhance the α phase precipitation due the introduction of lattice defects such as dislocations or grain boundaries, which act as preferential nucleation sites. Moreover, in HPT-deformed material, α precipitates are small and equiaxed, contrary to the α lamellae in the non-deformed material. ω phase formation is suppressed due to massive α precipitation and consequent element partitioning. Despite that, HPT-deformed material after ageing exhibits the high microhardness exceeding 450 HV.

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