scholarly journals Microstructure Evolution and Mechanical Stability of Supersaturated Solid Solution Co-Rich Nanocrystalline Co-Cu Produced by Pulsed Electrodeposition

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2616 ◽  
Author(s):  
Killang Pratama ◽  
Jenifer Barrirero ◽  
Frank Mücklich ◽  
Christian Motz
Keyword(s):  
Solid Solution ◽  
Supersaturated Solid Solution ◽  
The Other ◽  
Bending Test ◽  
High Yield ◽  
Grain Coarsening ◽  
Bending Tests ◽  
Annealing Temperatures ◽  
Other Hand ◽  
Pulsed Electrodeposition

Thick films of supersaturated solid solution nanocrystalline Co-Cu (28 at.% Cu) were synthesized through the pulsed electrodeposition technique. Microstructural changes of nanocrystalline Co-Cu were intensively studied at various annealing temperatures. Annealing at 300 °C results in a spinodal decomposition within the individual grains, with no grain coarsening. On the other hand, distinct phase separation of Co-Cu is detected at annealing temperatures beyond 400 °C. Static micro-bending tests show that the nanocrystalline Co-Cu alloy exhibits a very high yield strength and ductile behavior, with no crack formation. Static micro-bending tests also reported that a large plastic deformation is observed, but no microstructure change is detected. On the other hand, observation on the fatigue resistance of nanocrystalline Co-Cu shows that grain coarsening is observed after conducting the cyclic micro-bending test.

Anisotropic Microstructure and Hydrogen Permeability of Nb-Ti-Ni Duplex Phase Alloy Prepared by Hot Forging-Rolling Technique

2006 ◽  
Vol 980 ◽  
Author(s):  
Sho Tokui ◽  
Kazuhiro Ishikawa ◽  
Kiyoshi Aoki
Keyword(s):  
Solid Solution ◽  
Hydrogen Embrittlement ◽  
Hydrogen Permeability ◽  
Rolling Direction ◽  
Hot Forging ◽  
The Other ◽  
Rolling Reduction ◽  
Eutectic Microstructure ◽  
Ni Alloys ◽  
Other Hand

AbstractIt has been demonstrated that the as-cast Nb40Ti30Ni30 duplex phase alloy, which consists of the primary (Nb, Ti) solid solution and the fine lamellar type eutectic {TiNi+(Nb, Ti)} phase, shows higher hydrogen permeability ¶ than that of pure Pd without the hydrogen embrittlement at 673K. In this alloy, the eutectic phase contributes to the suppression of the hydrogen embrittlement, while the primary one does mainly to the hydrogen permeation. It is important to note that even if the eutectic microstructure disappears and is replaced by the small spherical (Nb, Ti) phase embedded in the TiNi matrix by rolling and subsequent annealing, its high hydrogen permeability and large resistance to the hydrogen embrittlement are sustained. Furthermore, the present authors have observed that the primary (Nb, Ti) phase is largely elongated along the rolling direction. Consequently, it is expected that rolled and annealed Nb-Ti-Ni alloys show the large anisotropy of the microstructure and the hydrogen permeability. In the present work, the microstructure and hydrogen permeability ¶nof the Nb40Ti30Ni30 alloy after rolling and annealing treatments are examined in order to develop highly hydrogen permeable alloys utilizing the anisotropic microstructure.The primary (Nb, Ti) phase and the very fine eutectic {TiNi+(Nb, Ti)} phase are observed in the as-cast Nb40Ti30Ni30 alloy by scanning electron microscopy (SEM). The X-ray diffractometry (XRD) indicates that this alloy consists of the B2-TiNi intermetallic compounds and the bcc- (Nb, Ti) solid solution. The primary (Nb, Ti) phase is largely elongated along the rolling direction by forging and subsequent rolling at 1173 K. On the other hand, the eutectic microstructure becomes unclear with increasing the rolling reduction. The composite alloys in which the (Nb, Ti) phase is elongated along to the rolling direction are obtained by 69 % rolling reduction. ¶n of this sample is four times higher than that of as-cast one. On the other hand, ¶ for the sample vertical to the rolling direction is reduced to about one third of that of as-cast one. Thus, the hydrogen permeability of the Nb40Ti30Ni30 alloy varies about ten times or more depending on the direction of the primary¡]Nb, Ti¡^ phase. We conclude that it is possible to produce highly hydrogen permeable Nb-Ti-Ni alloys using the anisotropy of the microstructure prepared by hot forging and rolling.

scholarly journals GROUND WATER IN GRANITE ROCKS AND TECTONIC MODELS

1972 ◽  
Vol 3 (3) ◽  
pp. 111-129 ◽  
Author(s):  
INGEMAR LARSSON
Keyword(s):  
Ground Water ◽  
Systematic Study ◽  
The Other ◽  
High Yield ◽  
Rock Mechanic ◽  
Granite Rock ◽  
Other Hand ◽  
Uniaxial Testing ◽  
Granite Rocks ◽  
Deformation Plane

A systematic study has been carried out concerning ground water in faults and fractures in a granite rock and the results are compared with those of uniaxial testing of granite specimens in rock mechanic laboratories. Dikes of diabase intersect the granite and indicate the plane of deformation syntectonic to the dikes. A collection of the tectonic data from the granite is statistically treated and the tectonic picture of the area fits very well into the deformation plane, indicated by the intrusion (Jotnian). The faults and fractures of the granite are, according to their position in relation to the plane of deformation, hypothetically interpreted as tension and shear faults. The faults in shear position are supposed to be tight and have very little ground water. The tension faults, on the other hand, are supposed to be open and to be capable of a high yield of ground water. This hypothesis is tested by core-drillings, percussion drillings and test pumping.

scholarly journals Characterization of Shock Wave Damages in Explosion Welded Mo/Cu Clads

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 501
Author(s):  
Pradeep Kumar Parchuri ◽  
Shota Kotegawa ◽  
Kazuhiro Ito ◽  
Hajime Yamamoto ◽  
Akihisa Mori ◽  
...  
Keyword(s):  
Shock Wave ◽  
Kinetic Energy ◽  
Plastic Strain ◽  
Intermediate Layer ◽  
Explosive Welding ◽  
The Other ◽  
Group Vi ◽  
Bending Tests ◽  
Other Hand

The shock wave damage during explosive welding has not been reported in a flyer Mo plate of the Mo/Cu clads. However, it would be an inevitable problem in group VI elements. This study was aimed to characterize the shock wave damage in the Mo plate, that is less brittle than a W plate, of explosive welded Mo/Cu clads. Cladding at low horizontal collision velocities leading to high collision angles was expected to enhance the shock wave damage, and the clads resulted in less elongation in bending tests. On the other hand, in the clads obtained at high horizontal collision velocities (HCVs) with low collision angles, their bending elongation increased significantly. The shock wave damage penetrated from the surface of a Mo plate to the Mo/Cu interface, and thus reducing thickness of a Mo plate of bending specimens increased bending plastic strain. The shock wave damage is associated with kinetic energy imparted to the flyer Mo plate, and thus loss of kinetic energy due to formation of an intermediate layer at the interface and reducing thickness of a flyer Mo plate would be very helpful for decrease of shock wave damage.

Predicting the Bending Size Dependency in Polymer Nanofiber Elasticity

2011 ◽  
Vol 236-238 ◽  
pp. 2179-2182
Author(s):  
Bo Yuan ◽  
Qun Feng Liu ◽  
Cai Lin ◽  
Xiao Feng Chen
Keyword(s):  
Model Prediction ◽  
Size Dependence ◽  
The Other ◽  
Bending Test ◽  
Bending Tests ◽  
Size Dependency ◽  
Polymer Nanofiber ◽  
Polymeric Nanofibers ◽  
Strain Gradient Model ◽  
Good Agreement

In this paper, a strain gradient model is constructed to predict the bending size dependence of the elastic property of nanofibers under three-point tests. The model prediction shows that there are two kinds of size dependency for the bending tests: one is related to the diameter of the nanofiber, which can be named as Diameter Size Dependency (D-SD), the other is related to the length of the nanofiber, which can be termed as Length Size Dependency (L-SD). Mechanical testing on PCL nanofibers was performed to verify the model for D-SD, and good agreement is found between the model prediction and the data obtained in the experiment. The model can be applied to explain the size dependency in bending test for polymeric nanofibers.

ANALYSIS ON THE MICROSTRUCTURE OF THE AS-CAST AND EXTRUDED Mg-(6-10)Li-3Al-Ce-Ca ALLOYS

2009 ◽  
Vol 23 (06n07) ◽  
pp. 920-926 ◽  
Author(s):  
LIREN CHENG ◽  
ZHANYI CAO ◽  
RUIZHI WU ◽  
MILIN ZHANG
Keyword(s):  
Solid Solution ◽  
Microstructural Characterization ◽  
Eutectic Structure ◽  
The Other ◽  
Β Phase ◽  
Other Hand ◽  
Long Rod

Microstructural characterization of as-cast and extruded experimental alloys as (A) Mg -6.86 Li -3.02 Al -1.12 Ce -0.7 Ca (B) Mg -8.15 Li -3.07 Al -1.12 Ce -0.72 Ca (C) Mg -10.54 Li -3.54 Al -1.23 Ce -0.94 Ca are researched in this paper. The results show that the as-cast specimens of (A) and (B) are composed of α ( Mg ) phase, β ( Li ) phase, rod-like and bulk Al 2 Ce compound. On the other hand, β phase ( Li ), bulk and rod-like Al 2 Ce compound, Al2 Ca compound at boundaries are observed in the as-cast (C) alloy. The addition of Ce and Ca also shows in the microstructure the presence of Al - Ce - Ca phase, a solid solution of Ca in Al 2 Ce compound. In the extruding alloys, the microstructure is refined and the β phase has the effect of coordination during deformation. The long rod-like and the bulk compounds become short rods and fine clumps distributing evenly in the extruding direction after extruding process. The microstructure of extruded Mg -10.54 Li -3.54 Al -1.23 Ce -0.94 Ca alloy testified the existence of eutectic structure.

THE SYSTEMS Li2SO4–K2SO4–H2O AND Li2SO4–Na2SO4–H2O AT 25 °C.

1958 ◽  
Vol 36 (1) ◽  
pp. 171-175 ◽  
Author(s):  
A. N. Campbell ◽  
E. M. Kartzmark
Keyword(s):  
Solid Solution ◽  
Transition Temperature ◽  
Sodium Sulphate ◽  
Double Salt ◽  
The Other ◽  
Other Hand ◽  
Lithium Sulphate

The 25° isotherm of the system Li2SO4–K2SO4–H2O shows the existence of the double salt, Li2SO4. K2SO4, whereas that of the system Li2SO4–Na2SO4–H2O yields no double salt but extensive solid solution of lithium sulphate in sodium sulphate. On the other hand, a study at 39.5 °C. of the latter system shows that the double salt, Li2SO4. Na2SO4, does form at this temperature, accompanied as before by solid solution of lithium sulphate in sodium sulphate. The transition temperature for the reaction[Formula: see text]is 29.3 °C. A further transition, of unknown nature, occurs between 49° and 57°.

scholarly journals Degradation of Polycarbonate by a Polyester-Degrading Strain, Amycolatopsis sp. Strain HT-6

1999 ◽  
Vol 65 (9) ◽  
pp. 4220-4222 ◽  
Author(s):  
Hardaning Pranamuda ◽  
Rungsima Chollakup ◽  
Yutaka Tokiwa
Keyword(s):  
Cell Growth ◽  
Liquid Culture ◽  
The Other ◽  
High Yield ◽  
Other Hand

ABSTRACT Amycolatopsis sp. strain HT-6, a poly(tetramethylene succinate) (PTMS)-degrading actinomycete, was observed to degrade poly(tetramethylene carbonate) (PTMC). In a liquid culture with 150 mg of PTMC film, 59% degradation was achieved, but with a low yield of cell growth. On the other hand, PTMS copolymerized with a small amount of PTMC, forming a copolyester carbonate (PEC) that was completely and rapidly degraded with a high yield of cell growth.

New Route Synthesis of Styryl Pyrones: High Yield Synthesis, Reactions and Spectral Properties of 2-Phenyl-6-Styryl-4-Pyrones

2005 ◽  
Vol 2005 (10) ◽  
pp. 654-656 ◽  
Author(s):  
Abdel Moneim El-Ghanam
Keyword(s):  
Hydrazine Hydrate ◽  
Spectral Properties ◽  
Sodium Ethoxide ◽  
Hydroxylamine Hydrochloride ◽  
The Other ◽  
High Yield ◽  
Phosphorus Pentasulfide ◽  
Other Hand ◽  
Synthesis Reactions ◽  
Derivatives Of

2-Phenyl-6-styryl-4-pyrone derivatives have been synthesised from the reaction of ethyl phenylpropiolate with benzylideneacetone derivatives in the presence of sodium ethoxide. Treatment of styrylpyrone with phosphorus pentasulfide gave the corresponding styrylpyran-4-thione which on treatment with hydroxylamine hydrochloride and aqueous methylamine afforded the corresponding oxime and 1-methyl-2-phenyl-6-styrylpyridine-4(1H)-thione, respectively. On the other hand, styrylpyran-4-thione reacted with malononitrile to give pyrolylidenemalononitrile which on treatment with bidentate reagents, hydrazine hydrate, hydroxylamine hydrochloride, thiourea, and thiosemicarbazide afforded the corresponding styrylspiropyran derivatives of pyrazole, 1,2-oxazole or 1,3-thiazine, respectively.

scholarly journals Reactivity of T-Nb2O5 or H-Nb2O5 towards V2O5. Synthesis in the solid state and properties of V4Nb18O55

2009 ◽  
Vol 7 (2) ◽  
pp. 222-227 ◽  
Author(s):  
Piotr Tabero ◽  
Elzbieta Filipek ◽  
Mateusz Piz
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
Solid State ◽  
Ir Spectra ◽  
Ir Spectrum ◽  
The Other ◽  
Other Hand ◽  
Structural Relations

AbstractThe IR spectrum of V4Nb18O55 has been compared with the IR spectra of selected niobates of known structures to show structural relations between these compounds. This comparison shows that V4Nb18O55 has crystal structure related to T-Nb2O5, W16Nb18O94 and Ba2NaNb5O15. On the other hand, reaction between V2O5 and H-Nb2O5 yields a solid solution of V2O5 in VNb9O25. It has been proposed two models of synthesized solid solution with formulas V1+xNb9-xO25 or V1+xNb9O25+5x/2.Independently of Nb2O5 polymorph, used for synthesis, the metastable compound VNbO5 cannot be synthesized in the solid state below 650°C

Orientation Relationship Between the bcc and σ Phases in Cr-Co Alloys

2006 ◽  
Vol 980 ◽  
Author(s):  
Toshihiro Doi ◽  
Makoto Tanimura ◽  
Yasumasa Koyama
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structure Formation ◽  
Orientation Relationship ◽  
The Other ◽  
Annealing Temperatures ◽  
Other Hand ◽  
Transmission Electron ◽  
The Common ◽  
Co Alloys

AbstractTo obtain deeper understanding of the Ð structure, the formation of the Ð structure in the (bcc¨bcc+Ð) reaction at 873K and 1173K have been investigated by transmission electron microscopy. As for the orientation relationship between the bcc and Ð structures, as a results, both the common first relation of [110]bcc//[110]Ð and three second relations given by α=0°, 33°, and 64° were found in the 1173K annealing, where α is an angle between the [_110]bcc and [001]Ð directions. In the 873K annealing, on the other hand, there was only one second relation with α=0°. Based on the α=0° relation found in both annealing temperatures, the features of atomic shifts in the Ð-structure formation were also discussed.

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