Anomalous effect of grain size on the room-temperature bendability of Mg–Gd alloy sheet

Pure dense silicon carbide (SiC) ceramics were obtained via the high-temperature physical vapor transport (HTPVT) method using graphite paper as the growth substrate. The phase composition, the evolution of microstructure, the thermal diffusivity and thermal conductivity at RT to 200∘C were investigated. The obtained samples had a relative density of higher than 98.7% and a large grain size of 1[Formula: see text]mm, the samples also had a room-temperature thermal conductivity of [Formula: see text] and with the temperature increased to 200∘C, the thermal conductivity still maintained at [Formula: see text].

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Experimental and Numerical Investigation of the ECAP Processed Copper: Microstructural Evolution, Crystallographic Texture and Hardness Homogeneity

Metals ◽

10.3390/met11040607 ◽

2021 ◽

Vol 11 (4) ◽

pp. 607

Author(s):

A. I. Alateyah ◽

Mohamed M. Z. Ahmed ◽

Yasser Zedan ◽

H. Abd El-Hafez ◽

Majed O. Alawad ◽

...

Keyword(s):

Grain Size ◽

Equal Channel Angular Pressing ◽

Cross Section ◽

Room Temperature ◽

Pure Copper ◽

High Density ◽

Ecap Processing ◽

Heterogeneous Distribution ◽

Angular Pressing ◽

Average Grain Size

The current study presents a detailed investigation for the equal channel angular pressing of pure copper through two regimes. The first was equal channel angular pressing (ECAP) processing at room temperature and the second was ECAP processing at 200 °C for up to 4-passes of route Bc. The grain structure and texture was investigated using electron back scattering diffraction (EBSD) across the whole sample cross-section and also the hardness and the tensile properties. The microstructure obtained after 1-pass at room temperature revealed finer equiaxed grains of about 3.89 µm down to submicrons with a high density of twin compared to the starting material. Additionally, a notable increase in the low angle grain boundaries (LAGBs) density was observed. This microstructure was found to be homogenous through the sample cross section. Further straining up to 2-passes showed a significant reduction of the average grain size to 2.97 µm with observable heterogeneous distribution of grains size. On the other hand, increasing the strain up to 4-passes enhanced the homogeneity of grain size distribution. The texture after 4-passes resembled the simple shear texture with about 7 times random. Conducting the ECAP processing at 200 °C resulted in a severely deformed microstructure with the highest fraction of submicron grains and high density of substructures was also observed. ECAP processing through 4-passes at room temperature experienced a significant increase in both hardness and tensile strength up to 180% and 124%, respectively.

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Magnetic Properties of Sputtered Fe-O and Co-O Thin Films

MRS Proceedings ◽

10.1557/proc-403-701 ◽

1995 ◽

Vol 403 ◽

Cited By ~ 1

Author(s):

D. V. Dimitrov ◽

A. S. Murthy ◽

G. C. Hadjipanayis ◽

C. P. SWANN

Keyword(s):

Grain Size ◽

Low Temperatures ◽

Room Temperature ◽

Oxide Films ◽

X Ray Diffraction ◽

Dc Magnetron Sputtering ◽

Large Shift ◽

X Ray ◽

Grain Size And Shape ◽

Spherical Grains

AbstractFe-O and Co-O films were prepared by DC magnetron sputtering in a mixture of Ar and O2 gases. By varying the oxygen to argon ratio, oxide films with stoichiometry FeO, Fe3O4, α-Fe2O3, CoO and Co3O4 were produced. TEM studies showed that the Fe – oxide films were polycrystalline consisting of small almost spherical grains, about 10 nm in size. Co-O films had different microstructure with grain size and shape dependent on the amount of oxygen. X-ray diffraction studies showed that the grains in Fe-O films were randomly oriented in contrast to Co-O films in which a <111> texture was observed. Pure FeO and α-Fe2O3 films were found to be superparamagnetic at room temperature but strongly ferromagnetic at low temperatures in contrast to the antiferromagnetic nature of bulk samples. A very large shift in the hysteresis loop, about 3800 Oe, was observed in field cooled Co-CoO films indicating the presence of a large unidirectional exchange anisotropy.

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Effect of grain size on twinning behavior of pure titanium at room temperature

Materials Science and Engineering A ◽

10.1016/j.msea.2021.142060 ◽

2021 ◽

Vol 827 ◽

pp. 142060

Author(s):

Bingshu Wang ◽

Huimin Liu ◽

Yonggan Zhang ◽

Baoxue Zhou ◽

Liping Deng ◽

...

Keyword(s):

Grain Size ◽

Room Temperature ◽

Pure Titanium

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ATOMIC FORCE MICROSCOPY AND XRD ANALYSIS OF SILVER FILMS DEPOSITED BY THERMAL EVAPORATION

International Journal of Modern Physics B ◽

10.1142/s021797920603319x ◽

2006 ◽

Vol 20 (02) ◽

pp. 217-231 ◽

Cited By ~ 4

Author(s):

MUHAMMAD MAQBOOL ◽

TAHIRZEB KHAN

Keyword(s):

Atomic Force Microscopy ◽

Grain Size ◽

Surface Characterization ◽

Room Temperature ◽

Thermal Evaporation ◽

Xrd Analysis ◽

Force Microscopy ◽

Atomic Force ◽

Average Grain Size ◽

20 Nm

Thin films of pure silver were deposited on glass substrate by thermal evaporation process at room temperature. Surface characterization of the films was performed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Thickness of the films varied between 20 nm and 72.8 nm. XRD analysis provided a sharp peak at 38.75° from silver. These results indicated that the films deposited on glass substrates at room temperature are crystalline. Three-dimension and top view pictures of the films were obtained by AFM to study the grain size and its dependency on various factors. Average grain size increased with the thickness of the deposited films. A minimum grain size of 8 nm was obtained for 20 nm thick films, reaching 41.9 nm when the film size reaches 60 nm. Grain size was calculated from the information provided by the XRD spectrum and averaging method. We could not find any sequential variation in the grain size with the growth rate.

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Is Superplasticity in the Future of Nanophase Materials?

MRS Proceedings ◽

10.1557/proc-196-59 ◽

1990 ◽

Vol 196 ◽

Cited By ~ 13

Author(s):

R. W. Siegel

Keyword(s):

Mechanical Properties ◽

Grain Size ◽

Room Temperature ◽

Grain Boundary Sliding ◽

Atomic Clusters ◽

Diffusional Creep ◽

Ultrafine Grain ◽

Grain Sizes ◽

Nanophase Materials ◽

Boundary Sliding

ABSTRACTThe ultrafine grain sizes and high diffusivities in nanophase materials assembled from atomic clusters suggest that these materials may have a strong tendency toward superplastic mechanical behavior. Both small grain size and enhanced diffusivity can be expected to lead to increased diffusional creep rates as well as to a significantly greater propensity for grain boundary sliding. Recent mechanical properties measurements at room temperature on nanophase Cu, Pd, and TiO2, however, give no indications of superplasticity. Nonetheless, significant ductility has been clearly demonstrated in these studies of both nanophase ceramics and metals. The synthesis of cluster-assembled nanophase materials is described and the salient features of what is known of their structure and mechanical properties is reviewed. Finally, the answer to the question posed in the title is addressed.

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Indentation Creep of Molybdenum: Comparison Between Thin Film and Bulk Material

MRS Proceedings ◽

10.1557/proc-356-651 ◽

1994 ◽

Vol 356 ◽

Cited By ~ 3

Author(s):

K. B. Yoder ◽

D. S. Stone ◽

J. C. Lin ◽

R. A. Hoffmann

Keyword(s):

Thin Film ◽

Grain Size ◽

Room Temperature ◽

Bulk Material ◽

High Hardness ◽

Rate Sensitivity ◽

Indentation Creep ◽

Creep Properties ◽

Measurement Path ◽

Arc Evaporation

AbstractIndentation creep, load relaxation, and rate-change experiments probe room temperature and 80°C creep properties of a 1.3 μm-thick molybdenum film on silicon. The film, with 0.51 GPa compressive stress, 8 GPa hardness and estimated 40 nm grain size, was deposited using steered-arc evaporation at -17V bias. Despite its small grain size and high hardness, the thin film behaves like bulk molybdenum does: the rate sensitivity of the hardness is only weakly-dependent on measurement path (as with bulk material), and activation volumes calculated based on strain rate sensitivity are consistent with those of bulk molybdenum We suspect deformation mechanisms are similar to those in bulk molybdenum under similar conditions.

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Effects of grain size on room temperature deformation behavior of Zn–22Al alloy under uniaxial and biaxial loading conditions

Materials Science and Engineering A ◽

10.1016/j.msea.2016.06.072 ◽

2016 ◽

Vol 672 ◽

pp. 78-87 ◽

Cited By ~ 8

Author(s):

M.E. Cetin ◽

M. Demirtas ◽

H. Sofuoglu ◽

Ö.N. Cora ◽

G. Purcek

Keyword(s):

Grain Size ◽

Deformation Behavior ◽

Room Temperature ◽

Biaxial Loading ◽

Temperature Deformation ◽

Loading Conditions ◽

Uniaxial And Biaxial Loading

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Investigation of Mechanical Properties of Nanostructured Titanium Processed by Warm ECAP Followed Cold Rolling

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.875-877.63 ◽

2014 ◽

Vol 875-877 ◽

pp. 63-67 ◽

Cited By ~ 1

Author(s):

Dinh van Hai ◽

Nguyen Trong Giang

Keyword(s):

Mechanical Properties ◽

Grain Size ◽

Tensile Strength ◽

Cold Rolling ◽

Room Temperature ◽

Pure Titanium ◽

Rolling Process ◽

Coarse Grain ◽

Nanostructured Titanium

In this work, ECAP technique was combined with cold rolling process in order to enhance mechanical properties and microstructure of pure Titanium. Coarse grain (CG) Titanium with original grain size of 150 μm had been pressed by ECAP at 425oC by 4, 8 and 12 passes, respectively. This process then was followed by rolling at room temperature with 35%, 55%, and 75% rolling strains. After two steps, mechanical properties such as strength, hardness and microstructure of processed Titanium have been measured. The result indicated significant effect of cold rolling on tensile strength, hardness and microstructure of ECAP-Titanium.

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