Search results

Ciphers in used marks of studied samples indicate numbers of ECAP passes (1T, 2M, 4B and so on).
Marking includes number of ECAP passes and region of section.
At that, in both cases this angle changes as number of ECAP passes increases.
In both Cu and Ti rods the substructure anisotropy decreases with the number of ECAP passes and in most grains some perfection of the crystalline lattice takes place (Fig. 4-6).
The fraction, characterized by ultrafine grains with the relatively low lattice distortion and dislocation density, grows gradually with number of ECAP passes.

The presence of large Mg2Si (dark inclusions) can be seen throughout the microstructure of secondary billet, and their distribution differ from grain to grain.
Moreover, it has denser secondary phase at the grain boundaries and large precipitates can be observed in some areas.
Time-to-failure of die is expressed in terms of total number of billets extruded before failure, T.
Hence, the dies do not run long when more number of secondary billets is used.
The trend clearly illustrates that die with extruding more number of secondary billets experienced less number of die correction and nitriding cycles.

Introduction The biomimetic synthesis route to forming complex functional materials [1] has recently gained prominent success in a number of areas [2-4].
To investigate the electrical connectivity of the grains within the YBCO powder, hysteresis loops were measured before and after the material was ground to separate the grains.
The addition of NaCl is the key to the appearance of platelike grains.
This value expresses the average grain connectivity within the sample.
In the dextran-mediated sample, the closely-aligned clusters of grains allow an intergranular current to pass, while in the chitosan-mediated sample, no such grain alignment exists, so individual grains remain electrically isolated.

We study the crystallization ratio, grain size of the silicon thin film specially.
The silicon thin film crystallization ratio and grain size changed sharply when PRF =70 W.
The physical properties such as crystallization ratio and grain size were tested by different instruments.
The grain sizes of the samples are estimated by relative formula and shown in the Fig.3.
This large number of high-energy H atom can cover the samples surface adequately and fully reorganize the irregular Si-Si structure.

. %) alloy was studied in the fine-grained state obtaining after equal channel angular pressing.
As a result, an equiaxed fine-grained structure with an average grain size of 1.1 μm was formed in the alloy.
(1a, 1b) SEM micrographs showing high magnifications of ductile fracture in area framed by number 1 in (a) and (b)
Sakai, K Tsuzaki, Ultrafine-grain structure formation in an Al-Mg-Sc alloy during warm ECAP, Metall.
Effect of grain refinement on jerky flow in an Al-Mg-Sc alloy, Metall.

Improvement in hardness and strength levels was achieved with an increased number of ARB cycles.
Among the SPD techniques, the ARB process allows us to manufacture a composite with a significant grain size reduction in the matrix, ultimately leading to ultrafine grain (UFG) microstructures [1].
There have been a number of past attempts related to ARB of titanium (Ti) and interstitial free (IF) steel in a single phase.
Reduction in individual layer thickness can be noticed with the increasing number of ARB cycles.
Tensile response of Ti/Al2024/IF composite and pre material As demonstrated in Fig. 4, stress under tension increased up to 650MPa with increasing number of ARB cycles.

Deformation at all test conditions leads to modification of the coarse-grained lamellar microstructure to fine-grained one.
The recrystallized grain size is less than the thickness of the initial α-plates.
Firstly, the rise of hydrogen concentration in the alloy can lead to an increase of the number of recrystallization nucleating centers.
Secondly, the hydrogen addition reduces α-grain growth as confirmed by measurements of grain size after annealing at 650°C in air (Fig.6).
Hydrogen influence on α-grain growth in CP titanium during annealing.

The experiments were carried using Taguchi optimization method, which studies a large number of variables with a small number of experiments.
The piezoelectric effect is averaged over all grains.
The substrate material also determines the sputtered grain size.
The proportionality of the gas mixture also controls the grain size of the piezoelectric material, when the ratio of Ar/O2 increases, the grain size also increases[14].
This will allow simultaneous evaluation of several parameters such as gas pressure, deposition time and RF power using a series number of trials.

Grain structure of Alloy 625, (b).
Grain structure of Sanicro 28.
In Sanicro 28, however, dense deformation twins and less dislocation (about 200000 observation number) can be observed.
The black lines are high angle grain boundary; the red lines are S3 twin boundary and the white ones are low angle grain boundary, (a).
Deformation twins appear only in some grains.

Powder mixture Pressure [GPa] Number of rotations Cu25Cr 2, 4, 6, 8 0.25, 1, 2, 5 W20Cu (6), 8 (1, 5), 0.25, 1, 2, 5 After HPT the disc-shaped samples were tested for their density, hardness and grain size.
These measurements were taken in gradual steps along the diameter at positions 0.5 mm apart, with a total number of 15.
a b Grain size analysis via SEM and XPA.
From the SEM data, grain sizes in the range of 50-500 nm were evaluated resulting from finer subgrains as being evident from the continuously changing contrast within the grains (Fig. 4).
Parameter description: m- median grain size, σ- variance, L0- volume weighted and d- area weighted grain size [7], r = radius.