Grain Size Effect on Deformation Twinning and De-Twinning in a Nanocrystalline Ni-Fe Alloy

The effect of grain size on the deformation twinning and de-twinning in a nanocrystalline Ni-Fe alloy was investigated using transmission electron microscopy. Specimens with different grain sizes were obtained by severely deforming an electrochemically deposited nanocrystalline Ni-20wt.% Fe alloy using high-pressure torsion, which resulted in continuous grain growth from an average grain size of ~ 21 nm in the as-deposited material to ~ 72 nm for the highest strain applied in this study. Results show that deformation de-twinning occurs at very small grain sizes while deformation twinning takes place when the grain size is larger than ~ 45 nm. The mechanism of the observed grain size effect on twinning and de-twinning is briefly discussed.

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Heterogeneity Effects in X-Ray Analysis*

Advances in X-ray Analysis ◽

10.1154/s0376030800001671 ◽

1961 ◽

Vol 5 ◽

pp. 335-354 ◽

Cited By ~ 7

Author(s):

Fernand Claisse ◽

Claude Samson

Keyword(s):

Grain Size ◽

Size Effect ◽

Mathematical Treatment ◽

Grain Size Effect ◽

Light Elements ◽

X Ray Diffraction ◽

Limited Region ◽

X Ray ◽

Grain Sizes ◽

Heterogeneity Effects

AbstractA fundamental quantitative treatment of the heterogeneity effects in X-ray fluorescence has been made. The theory predicts that the grain-size effect appears only in a limited region of grain sizes which depends on the wavelength of the primary radiation and the nature of the compounds in the mixture. With monochromatic radiation, the fluorescence intensity showed increase or decrease by a factor of a few units as grain size is decreased, A factor as large as 12, the theoretical value, has been observed in one particular experiment. Usually the grain-size effect can be eliminated by intensive grinding. For the light elements fine grinding is disastrous if long wavelengths are used. By an appropriate choice of the wavelength it is possible to eliminate the effect even without grinding. The mathematical treatment also predicts, but less rigorously, a grain-size effect in X-ray diffraction.The effect on the fluorescence intensities by changes in the chemical composition of the grains that contain the fluorescent element is predicted by the theory.These findings are discussed in relation to the analysis of elements when polychromatic beams are used.

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Effects of Microstructure on the Electrical Conductivity of SrCo0.8Fe0. 2O3_δ

MRS Proceedings ◽

10.1557/proc-575-315 ◽

1999 ◽

Vol 575 ◽

Cited By ~ 1

Author(s):

K. Zhang ◽

M. Miranova ◽

Y. L. Yang ◽

A. J. Jacobson ◽

K. Salama

Keyword(s):

Activation Energy ◽

Electrical Conductivity ◽

Grain Size ◽

Size Effect ◽

Temperature Region ◽

Grain Size Effect ◽

Average Grain Size ◽

Lower Temperature ◽

Lower Temperature Region ◽

Test Temperature Range

ABSTRACTThe effect of microstructure on the electrical conductivity of SrCO0.8Fe0.2O3_δ (SCFO) was investigated in air using a four-point dc method. In the test temperature range of 200 to 900 °C, the electrical conductivity of this material was observed to increase with the increase of the average grain size in the lower temperature region where the conductivity increases with the increase of the temperature. The activation energy is decreased with the increase of the grain size in this region, 0.04 ± 0.004 ev for 4.1μm sample and 0.01 ± 0.001 ev for 14.8 μm sample. When temperature is further increased, the conductivity of this material decreases with the increase of the temperature, and the grain size effect becomes less noticeable.

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Grain Size Effect on the Type VT1-0 Alloy Modified by Aluminum Ion Implantation

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.670.144 ◽

2015 ◽

Vol 670 ◽

pp. 144-151

Author(s):

Irina Kurzina ◽

Alisa Nikonenko ◽

Natalja Popova ◽

Elena L. Nikonenko ◽

Mark Kalashnikov

Keyword(s):

Mechanical Properties ◽

Grain Size ◽

Ion Implantation ◽

Size Effect ◽

Phase State ◽

Grain Size Effect ◽

Significant Modification ◽

Aluminum Ion ◽

Grain Sizes ◽

Aluminum Ions

The paper presents results of investigations of α-Ti microhardness modified by aluminum ions having diverse grain sizes, namely: 0.3 μm, 1.5 μm, and 17 μm. These investigations show that the decrease of the grain size and the additional ion implantation result in the significant modification of the structural and phase state of the alloy and its mechanical properties.

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GRAIN SIZE EFFECT ON THE COLOSSAL MAGNETORESISTANCE IN GRANULAR PEROVSKITE La0.7Pb0.3MnO3

Modern Physics Letters B ◽

10.1142/s021798490601202x ◽

2006 ◽

Vol 20 (29) ◽

pp. 1859-1865 ◽

Cited By ~ 1

Author(s):

S. L. YOUNG ◽

H. Z. CHEN ◽

M. C. KAO ◽

L. HORNG ◽

K. M. WU ◽

...

Keyword(s):

Grain Size ◽

Magnetic Susceptibility ◽

Size Effect ◽

Colossal Magnetoresistance ◽

Double Exchange ◽

Tunneling Effect ◽

Grain Size Effect ◽

Double Exchange Interaction ◽

Grain Sizes ◽

Ferromagnetic Ordering

Magnetic behaviors and transport properties in granular perovskite La 0.7 Pb 0.3 MnO 3 with different grain sizes have been synthesized. The results show that magnetic susceptibility, ferromagnetic ordering temperature and magnetoresistance are affected by the grain size. These compounds with different grain sizes exhibit two kinds of magnetoresistance origins, intragrain double exchange and intergrain interfacial tunneling. With the increasing grain size, the intrinsic transport is dominant while the extrinsic tunneling gradually disappears. Thus, the basis of magnetotransport mechanism is the result of competition between the double exchange interaction and the interfacial tunneling effect.

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Grain-size effect on the deformation mechanisms of nanostructured copper processed by high-pressure torsion

Journal of Applied Physics ◽

10.1063/1.1757035 ◽

2004 ◽

Vol 96 (1) ◽

pp. 636-640 ◽

Cited By ~ 139

Author(s):

X. Z. Liao ◽

Y. H. Zhao ◽

Y. T. Zhu ◽

R. Z. Valiev ◽

D. V. Gunderov

Keyword(s):

Grain Size ◽

High Pressure ◽

Size Effect ◽

High Pressure Torsion ◽

Deformation Mechanisms ◽

Grain Size Effect ◽

Nanostructured Copper

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Grain size effect on deformation twinning propensity in ultrafine-grained hexagonal close-packed titanium

Scripta Materialia ◽

10.1016/j.scriptamat.2013.06.001 ◽

2013 ◽

Vol 69 (5) ◽

pp. 428-431 ◽

Cited By ~ 41

Author(s):

J.L. Sun ◽

P.W. Trimby ◽

F.K. Yan ◽

X.Z. Liao ◽

N.R. Tao ◽

...

Keyword(s):

Grain Size ◽

Size Effect ◽

Deformation Twinning ◽

Grain Size Effect ◽

Hexagonal Close Packed ◽

Ultrafine Grained

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Grain size effect on piezoelectric properties of Sr2Nb2O7 ceramics

Journal of Advanced Dielectrics ◽

10.1142/s2010135x18200035 ◽

2018 ◽

Vol 08 (04) ◽

pp. 1820003 ◽

Cited By ~ 2

Author(s):

Tao Chen ◽

Zhiyong Zhou ◽

Ruihong Liang ◽

Xianlin Dong

Keyword(s):

Thermal Stability ◽

Grain Size ◽

Solid State ◽

Size Effect ◽

Solid State Reaction ◽

Piezoelectric Properties ◽

Solid State Reaction Method ◽

Grain Size Effect ◽

Reaction Method ◽

Grain Sizes

Grain size effect on piezoelectric properties and thermal stability of perovskite layer structured (PLS) Sr2Nb2O7 ceramics are investigated. The Sr2Nb2O7 ceramics with different average grain sizes from 1.2[Formula: see text][Formula: see text]m to 3.6[Formula: see text][Formula: see text]m were prepared in different sintering temperatures by solid state reaction method. The average grain size increases, accompanied by a higher relative density of up to 96%. Pure Sr2Nb2O7 ceramics with larger grain size show a remarkable [Formula: see text] of ([Formula: see text])pC/N while still with a very high [Formula: see text] of ([Formula: see text]C. The thermal depolarization temperature of samples with large grain sizes reach over 1200∘C and the thermal stability increased with increasing of grain size. The ferroelectric domains structure was observed by PFM and larger grain is easy to form ferroelectric domain then enhance piezoelectric properties. This study demonstrates enhanced piezoelectric properties can be achieved in pure Sr2Nb2O7 by solid state reaction method and bring great revitalization to the Sr2Nb2O7-based ceramics as a promising high-temperature piezoelectric material.

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