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Online since: March 2008
Authors: I. Alvarez-Armas, Suzanne Degallaix
All grades in
the ASTM specifications have their designations in the Unified Numbering System (UNS).
The most common duplex grade today is EN 1.4462 DSS (UNS S31803 / S32205), which is used in a great number of applications in a wide variety of product forms.
As a result of the rolled manufacture of the bars, the grain microstructure shows an elongated shape along the rolling direction.
The mean grain diameter in S32750 and S32205 is about 10 µm in both phases, while the grade S32900 has a mean ferritic and austenitic grain size of 10 µm and 5 µm, respectively.
Accordingly, dislocations can, many times, avoid the strong barrier of grain boundaries due to the coupling between phases.
The most common duplex grade today is EN 1.4462 DSS (UNS S31803 / S32205), which is used in a great number of applications in a wide variety of product forms.
As a result of the rolled manufacture of the bars, the grain microstructure shows an elongated shape along the rolling direction.
The mean grain diameter in S32750 and S32205 is about 10 µm in both phases, while the grade S32900 has a mean ferritic and austenitic grain size of 10 µm and 5 µm, respectively.
Accordingly, dislocations can, many times, avoid the strong barrier of grain boundaries due to the coupling between phases.
Online since: June 2020
Authors: Zhang Jian Zhou, Ling Zhi Chen, Yuan Gao, Qi Wang
In the near future, a number of advanced nuclear energy systems will operate at a rather high temperature level compared with currently running reactors in order to improve the thermal efficiency [9].
If the composition of AFA alloys are correctly designed, it will show single austenitic (γ) phase microstructure with equiaxed grains and annealing twins.
From Fig. 2 (a) and (b), it can be seen that a lot of precipitates with rod or needle shape formed inside the γ grains.
NiAl particles with round shape are found inside the α grains in the sample of 16Ni5Al, as seen in Fig. 2(d).
It was found that σ-FeCr precipitated along grain boundary in NbTi and NbTa doped AFA alloys, but not appeared in NbV added AFA alloy [18].
If the composition of AFA alloys are correctly designed, it will show single austenitic (γ) phase microstructure with equiaxed grains and annealing twins.
From Fig. 2 (a) and (b), it can be seen that a lot of precipitates with rod or needle shape formed inside the γ grains.
NiAl particles with round shape are found inside the α grains in the sample of 16Ni5Al, as seen in Fig. 2(d).
It was found that σ-FeCr precipitated along grain boundary in NbTi and NbTa doped AFA alloys, but not appeared in NbV added AFA alloy [18].
Online since: February 2011
Authors: Lian Chao Wang
According to the Scherrer formula (B=0.9λ/(cosθ)) ,the grain size of crystal NiO film increased with an increase of heating temperature.
The film heated at 300 °C for 30 min has a larger, more compact , regular square structure (Fig.5(a)) with the average grain size of NiO about 20nm.
The number of cycles can rapidly increase for the NiO films heated above the crystal temperature, and the films heated above 300°C retain good electrochromic reversibility after 500 cycles of coloring and bleaching.
As the films heated at 280 °C, crystallite NiO in the films , the electrochromic reversibility of the film is improved , the number of cycles rapidly increases.
(a) the relationship of the number of cycle for the film heated at different temperatures.
The film heated at 300 °C for 30 min has a larger, more compact , regular square structure (Fig.5(a)) with the average grain size of NiO about 20nm.
The number of cycles can rapidly increase for the NiO films heated above the crystal temperature, and the films heated above 300°C retain good electrochromic reversibility after 500 cycles of coloring and bleaching.
As the films heated at 280 °C, crystallite NiO in the films , the electrochromic reversibility of the film is improved , the number of cycles rapidly increases.
(a) the relationship of the number of cycle for the film heated at different temperatures.
Online since: April 2012
Authors: Antônio Gilson Barbosa de Lima, I. Batista dos Santos, L.P. de Lucena Silva
Looking at the graph it is clear that for the same Fourier number, the moisture content will depend on the dimensionless Biot number.
For higher Biot number, the smaller dimensionless moisture content within the solid, for the same Fourier number is obtained.
Figure 4 shows the average moisture content as a function of Fourier number for different aspect ratio and Biot number equal to 4.0.
For higher Biot number the solid dry quickly.
Hall: Drying and storage of grains and oilseeds.
For higher Biot number, the smaller dimensionless moisture content within the solid, for the same Fourier number is obtained.
Figure 4 shows the average moisture content as a function of Fourier number for different aspect ratio and Biot number equal to 4.0.
For higher Biot number the solid dry quickly.
Hall: Drying and storage of grains and oilseeds.
Online since: March 2004
Authors: Moo Young Huh, Soo Ho Park, Jong Heun Lee
Recent researches on FSS disclosed that the distribution of orientations of
grains in FSS is responsible for the formation of these surface defects (e.g. [4]).
In this sample, the type of textures and the intensity of texture components hardly changed with increasing number of rolling passes and the cold rolling textures indeed resembled to the initial texture (Fig. 1a).
Generally, the intensity of rolling texture components sharpens with increasing rolling reductions because the dislocation slip in the crystallographic slip systems gives rise to a rotation of grains to one of stable orientations under the imposed strain state during rolling.
In these models the individual crystallites are assumed to deform by slip on a number of crystallographic slip system so as to accommodate the prescribed macroscopic strain rate ij�& .
Journal Title and Volume Number (to be inserted by the publisher) [7] O.
In this sample, the type of textures and the intensity of texture components hardly changed with increasing number of rolling passes and the cold rolling textures indeed resembled to the initial texture (Fig. 1a).
Generally, the intensity of rolling texture components sharpens with increasing rolling reductions because the dislocation slip in the crystallographic slip systems gives rise to a rotation of grains to one of stable orientations under the imposed strain state during rolling.
In these models the individual crystallites are assumed to deform by slip on a number of crystallographic slip system so as to accommodate the prescribed macroscopic strain rate ij�& .
Journal Title and Volume Number (to be inserted by the publisher) [7] O.
Online since: March 2013
Authors: Wen Xue Wang, Shijie Zhu, Jun Feng Hu, Yukiko Nakahara
Si3N4 grain has an aspect ratio of about 4 and a diameter of 0.2-1μm. 20wt% SiC whisker was added to Si3N4 and then 12wt% Al2O3 and Y2O3 were added to the mixed powder as sintering additives with de-ionized water and some deflocculant in an alumina ball mill for 46 h.
The reason for this phenomenon may be that glass phases between grains boundaries melted and flowed out at high temperatures, which lead to the reduction in strength.
When the Eq.1 is used for analyzing the crack healing rate with different number of indents, the calculated strength ratio of specimens with different number of indents before and after heat treatment is shown in Table 1.
The calculated strength ratio does not depend on number of indents.
Table 1 Strength ratio of specimens before and after heat treated at 1300for 1 h Number of indents 3 5 15 22 1.54 1.73 1.69 1.75 4.
The reason for this phenomenon may be that glass phases between grains boundaries melted and flowed out at high temperatures, which lead to the reduction in strength.
When the Eq.1 is used for analyzing the crack healing rate with different number of indents, the calculated strength ratio of specimens with different number of indents before and after heat treatment is shown in Table 1.
The calculated strength ratio does not depend on number of indents.
Table 1 Strength ratio of specimens before and after heat treated at 1300for 1 h Number of indents 3 5 15 22 1.54 1.73 1.69 1.75 4.
Online since: October 2014
Authors: Zhe Hui Wu, Na Su, Ji Min Liu, Tai An Liu, Xin Jun An, Chang Qing Yan
Newest data are memorized on the most fine-grained time layer and older data are memorized on the more coarse-grained time layer.
Each pattern is assigned a logarithmic tilted time window table to compress the support number of itemsets in child windows at different periods.
We use an attenuation coefficient, ,, to lessen the significance of each data record over time, where n is the number of time window, n=, where t denotes the time of data record arrived.
Then the number of newest time window, n1=0 and so on as Fig.1.
For all the itemsets, whose frequency is above zero, we use frequency list to record the approximate frequency count f and its maximum possible error . l denotes the number of counter queue layer.
Each pattern is assigned a logarithmic tilted time window table to compress the support number of itemsets in child windows at different periods.
We use an attenuation coefficient, ,, to lessen the significance of each data record over time, where n is the number of time window, n=, where t denotes the time of data record arrived.
Then the number of newest time window, n1=0 and so on as Fig.1.
For all the itemsets, whose frequency is above zero, we use frequency list to record the approximate frequency count f and its maximum possible error . l denotes the number of counter queue layer.
Online since: January 2012
Authors: Hang Gao, Ben Wang, Fang Hong Sun, Jian Guo Zhang
For the characterization, scanning electron microscopy (SEM) is adopted to investigate the surface morphology, microstructure and grain size, and the Raman spectroscopy is used to examine the diamond purity.
The shift from the 1332 cm-1 in wave number is owing to the presence of residual stress in the films.
Flank wear of the two kinds of drills is observed and measured at regular number of holes intervals.
Fig.6 displays values of the measured flank wear versus the number of drilled holes.
Fig.6 Tool wear of flank face as a function of the number of drilled holes Machining quality.
The shift from the 1332 cm-1 in wave number is owing to the presence of residual stress in the films.
Flank wear of the two kinds of drills is observed and measured at regular number of holes intervals.
Fig.6 displays values of the measured flank wear versus the number of drilled holes.
Fig.6 Tool wear of flank face as a function of the number of drilled holes Machining quality.
Online since: September 2013
Authors: You Ye Zheng, Shun Bao Gao, Jian Guo Wang
Analysis of prospecting cases
Xiongcun Cu(Au) deposits is one of the large copper mine that located in the middle of the island-arc magma metallogenic belt at present, there are a large number of intrusions related with Middle Jurassic hornblende-quartz-diorite-porphyrite in the mining area [2].
Black-mica-granite is the largest area of the rock exposed in the mining area, medium grained porphyritic structure, phenocrysts mainly for potassium feldspar.
The mineralization of Xiongcun deposits was strong altered that occurs in the quartz diorite porphyry, and fine - grained tuff, which was shown in table.2.
Mineralization of Xiongcun deposits was not obvious, hornblende quartz diorite and its surrounding rock (fine-grained tuff) mineralizated generally.
The ore-hunting indicator is quartz, diorite, porphyrite, which located in fine-grained tuff with ocular spherical quartz phenocrysts hornblende, the surface have burning skin and iron dye in large scale, and there propylitization, pyrite-sericition in common, silicification especially.
Black-mica-granite is the largest area of the rock exposed in the mining area, medium grained porphyritic structure, phenocrysts mainly for potassium feldspar.
The mineralization of Xiongcun deposits was strong altered that occurs in the quartz diorite porphyry, and fine - grained tuff, which was shown in table.2.
Mineralization of Xiongcun deposits was not obvious, hornblende quartz diorite and its surrounding rock (fine-grained tuff) mineralizated generally.
The ore-hunting indicator is quartz, diorite, porphyrite, which located in fine-grained tuff with ocular spherical quartz phenocrysts hornblende, the surface have burning skin and iron dye in large scale, and there propylitization, pyrite-sericition in common, silicification especially.
Online since: March 2016
Authors: Kei Ameyama, Chao Li Ma, Hai Jun Yang, Hui Li, Yi Tan Zhang, Zhi Guo Liu
Number
Composition
0
40%B4C+60%Al2024
1
32%B4C+68%Al2024
2
16%B4C+84%Al2024
Milling.
At the same time, the dislocation density of the matrix is increased by the addition of micron sized particles, which can improve the strength of the composites. [18] Grain boundaries act as sources and sinks for dislocations, and dislocations can merge into grain boundaries when no force is applied and can re-emit under an applied force. [19] What’s more, the content of B4C was less, so the deformation of the matrix was not limited.
Optimization of strength and ductility in nanocrystalline and ultrafine grained metals[J].
Al–Mg alloy engineered with bimodal grain size for high strength and increased ductility[J].
Deformation and activation volumes of cryomilled ultrafine-grained aluminum[J].
At the same time, the dislocation density of the matrix is increased by the addition of micron sized particles, which can improve the strength of the composites. [18] Grain boundaries act as sources and sinks for dislocations, and dislocations can merge into grain boundaries when no force is applied and can re-emit under an applied force. [19] What’s more, the content of B4C was less, so the deformation of the matrix was not limited.
Optimization of strength and ductility in nanocrystalline and ultrafine grained metals[J].
Al–Mg alloy engineered with bimodal grain size for high strength and increased ductility[J].
Deformation and activation volumes of cryomilled ultrafine-grained aluminum[J].