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Online since: July 2013
Authors: Seppo Louhenkilpi, Jyrki Miettinen, Risto Vesanen, Jukka Laine
The ADC module applies thermodynamic chemical potential equality equations of paraequilibrium condition, material balance equations for the ferrite/austenite interface advancing in a spherical austeinite grain (earlier for carbon only but now also for nitrogen and boron) and regression formulas optimized from English and German CCT measurements, where the influencing solutes are C, Si, Mn, Cr, Mo and Ni.
In this case, the excess element (particularly hydrogen) can be concentrated in grain boundaries or micro holes (formed by plastic deformation), where it can take a gaseous form.
At low temperatures, the gas pressures can grow very high and cause cracks advancing along the grain boundaries of the expanding micro holes.
The developed function has been validated by a great number of experimental data.
The HOM module simulates: 1) Homogenization of composition profiles (microsegregation), 2) Compound (precipitate) growth or dissolution, 3) Ferrite growth or dissolution, 4) Growth of austenite grains (approximate method for low alloyed steels).
In this case, the excess element (particularly hydrogen) can be concentrated in grain boundaries or micro holes (formed by plastic deformation), where it can take a gaseous form.
At low temperatures, the gas pressures can grow very high and cause cracks advancing along the grain boundaries of the expanding micro holes.
The developed function has been validated by a great number of experimental data.
The HOM module simulates: 1) Homogenization of composition profiles (microsegregation), 2) Compound (precipitate) growth or dissolution, 3) Ferrite growth or dissolution, 4) Growth of austenite grains (approximate method for low alloyed steels).
Online since: October 2018
Authors: A.V. Verkhovykh, A.A. Mirzoev, D.A. Mirzaev
., form segregations at grain boundaries resulting in abrupt changes of mechanical properties [1].
But many steels contain a number of alloying elements, and it is not always easy to say if phosphorus causes brittleness by itself or as a result of interaction with other impurities.
Grabke, Equilibrium segregation of phosphorus at grain boundaries of Fe–P, Fe–C–P, Fe–Cr–P, and Fe–Cr–C–P alloys, Metal Science, 15 (1981) 401-408
Kimura, Effect of carbon on the grain boundary segregation of phosphorus in α-iron, Scripta Metallurgica, 17 (1983) 1325-1328
Hartmaier, Solubility of carbon in α-iron under volumetric strain and close to the Σ5 (310)[001] grain boundary: Comparison of DFT and empirical potential methods, Computational Materials Science, 50 (2011) 1088-1096
But many steels contain a number of alloying elements, and it is not always easy to say if phosphorus causes brittleness by itself or as a result of interaction with other impurities.
Grabke, Equilibrium segregation of phosphorus at grain boundaries of Fe–P, Fe–C–P, Fe–Cr–P, and Fe–Cr–C–P alloys, Metal Science, 15 (1981) 401-408
Kimura, Effect of carbon on the grain boundary segregation of phosphorus in α-iron, Scripta Metallurgica, 17 (1983) 1325-1328
Hartmaier, Solubility of carbon in α-iron under volumetric strain and close to the Σ5 (310)[001] grain boundary: Comparison of DFT and empirical potential methods, Computational Materials Science, 50 (2011) 1088-1096
Online since: March 2024
Authors: Filip Khestl, Bohdan Sousedik, Vlastimil Bilek, Lucie Malíková, Lukáš Prochazka
Consequently, it is characterized by a high proportion of unhydrated cement grains together with a dense (micro)structure.
Above this value, the mixture contains enough water to ensure the hydration of the cement grains and fill the small capillary pores.
The measurement of the resistance to F&T cycles is based on the testing of mechanical properties (strengths and dynamic modulus of elasticity) of specimens subjected to a specified number of F&T cycles.
These values decreased when high-quality sand grains were substituted with low-strength LWA grains.
Above this value, the mixture contains enough water to ensure the hydration of the cement grains and fill the small capillary pores.
The measurement of the resistance to F&T cycles is based on the testing of mechanical properties (strengths and dynamic modulus of elasticity) of specimens subjected to a specified number of F&T cycles.
These values decreased when high-quality sand grains were substituted with low-strength LWA grains.
Online since: August 2010
Authors: Eun Sang Lee, Hon Jong Choi, Jung Taik Lee, Jong Koo Won
The number of
chips can be produced on a 300 mm wafer is roughly 2.5 times that on a 200 mm wafer[4].
The mechanical process is a removal machining with the polishing grains within slurry.
Mechanical factors are associated with polishing pad, polishing grain and physical correlation on the wafer surface.
Chemical factors are mainly decided by viscosity of slurry, velocity of wafer, hardness of grain, characteristics of pad and lubrication characteristics about the wafer curvature.
A case of lapping has mainly been known as material removal is determined by compressing, scratch of polishing grain.
The mechanical process is a removal machining with the polishing grains within slurry.
Mechanical factors are associated with polishing pad, polishing grain and physical correlation on the wafer surface.
Chemical factors are mainly decided by viscosity of slurry, velocity of wafer, hardness of grain, characteristics of pad and lubrication characteristics about the wafer curvature.
A case of lapping has mainly been known as material removal is determined by compressing, scratch of polishing grain.
Online since: August 2014
Authors: Lai Xing Cai, Ang Li, Shuang Liu, Qi Li
During the early period of SQ2, terrigenous clastic retrograded, fine grain argillaceous sediments superimposed on the coarse gravel rock, sand body decreased in numbers with thickness reduction.
Positive grain sequence is presented in the vertical.In the later period of SQ1,water leaved the basin ,sand body progressed, single sand bodies increased leading to thickess enlarging, reversed grain sequence is presented from the bottom in the vertical.
Grain sequence stacking pattern presents “thick→fine→thick”from the bottom to the top. the reversed order para-sequence sets caused by the lake regression and progradation set on the positive para-sequence sets caused by the lake transgression and retrogradation.
Positive grain sequence is presented in the vertical.In the later period of SQ1,water leaved the basin ,sand body progressed, single sand bodies increased leading to thickess enlarging, reversed grain sequence is presented from the bottom in the vertical.
Grain sequence stacking pattern presents “thick→fine→thick”from the bottom to the top. the reversed order para-sequence sets caused by the lake regression and progradation set on the positive para-sequence sets caused by the lake transgression and retrogradation.
Online since: June 2012
Authors: Yan Xiao, R.Z. Yang
Table 1 Summery of test results
Test type
N*
MV† [MPa]
SD‡
VC§
VC§ in GB
AI ll
Tension
Strength
16
82
16
20%
20%
10%
Modulus
16
10400
16
20%
Compression
strength
without cold glue-line
26
51
2.6
5%
13%
2.0%
Static bending
Strength
32
99
11
10%
11%
4%
Modulus
32
9400
927
10%
20%
3%
Shear strength
25
16
2
12%
20%
5%
*Number of specimens; †Mean value; ‡Standard deviation; §Variation coefficient; ll Accuracy index.
Perpendicular-to-grain stress along the hole edge (b=4d; material is red spruce) (taken from Ce´sar Echavarrı´a and Alexander Salenikovich 1998) As shown in Fig. 10, they depict the perpendicular-to-grain stress along the hole edge, and the tensile stresses are reported as positive.
Vega, Numerical and experimental analyses of multiple-dowel steel-to-timber joints in tension perpendicular to grain.
Quasi-non-linear fracture mechanics analysis of the splitting failure of single dowel joints loaded perpendicular to grain.
Perpendicular-to-grain stress along the hole edge (b=4d; material is red spruce) (taken from Ce´sar Echavarrı´a and Alexander Salenikovich 1998) As shown in Fig. 10, they depict the perpendicular-to-grain stress along the hole edge, and the tensile stresses are reported as positive.
Vega, Numerical and experimental analyses of multiple-dowel steel-to-timber joints in tension perpendicular to grain.
Quasi-non-linear fracture mechanics analysis of the splitting failure of single dowel joints loaded perpendicular to grain.
Online since: December 2010
Authors: J. J. Chen, Wilson W. S. Fung, Leo G. Li, Albert K.H. Kwan
Its molecule looks like a comb, with a backbone formed of an active-monomer and a number of side chains formed of graft copolymers.
Such packing density improvement can be attributed to the dispersion effect of the SP, which avoids the formation of agglomerates and thus allows the cement grains to be closely packed.
With the saturation dosage of SP added, the packing density of the cement can be further improved upon the addition of fillers which fill the voids between the cement grains.
Since the particle size of LSF is just slightly finer than OPC, it cannot fill into the voids between the OPC grains so easily and consequently its filling effect is relatively small.
On the contrary, the SFC and CSF are much finer than OPC, so that they can effectively fill into the voids between the OPC grains and hence greatly improve the packing density.
Such packing density improvement can be attributed to the dispersion effect of the SP, which avoids the formation of agglomerates and thus allows the cement grains to be closely packed.
With the saturation dosage of SP added, the packing density of the cement can be further improved upon the addition of fillers which fill the voids between the cement grains.
Since the particle size of LSF is just slightly finer than OPC, it cannot fill into the voids between the OPC grains so easily and consequently its filling effect is relatively small.
On the contrary, the SFC and CSF are much finer than OPC, so that they can effectively fill into the voids between the OPC grains and hence greatly improve the packing density.
Online since: May 2014
Authors: Mayumi Suzuki, Yasuyuki Murata, Kyosuke Yoshimi
There is no precipitates are observed within grains and grain boundaries, thereby any static and dynamic precipitation effects could be ignored in the present investigation.
In deformation substructures, a+c dislocations (b = ) and/or c-dislocations (b = <0001>) are observed in a few grains (Fig.5).
However, the activation of a-dislocations are predominantly in most of the grains, thereby the cross-slip and/or prismatic slip affects creep rate in the Mg-Y and Mg-Y-Zn based alloy as the rate-controlling mechanism at the temperature range from 480 to 570 K.
This research has been partly supported by Grant-in-Aid for Scientific Research(C), KAKENHI (JSPS KAKENHI Grant Number 24560856); Japan Society for the Promotion of Science (JSPS).
In deformation substructures, a+c dislocations (b = ) and/or c-dislocations (b = <0001>) are observed in a few grains (Fig.5).
However, the activation of a-dislocations are predominantly in most of the grains, thereby the cross-slip and/or prismatic slip affects creep rate in the Mg-Y and Mg-Y-Zn based alloy as the rate-controlling mechanism at the temperature range from 480 to 570 K.
This research has been partly supported by Grant-in-Aid for Scientific Research(C), KAKENHI (JSPS KAKENHI Grant Number 24560856); Japan Society for the Promotion of Science (JSPS).
Online since: January 2022
Authors: Nur Azam Badarulzaman, Suzi Salwah Jikan, Rozainita Rosley, Muhammad Sufi Roslan, Siti Noraiza Ab Razak, Fahmiruddin Esa, Munira Khalid
Once icorr is determined, the following equation derived from Faraday's law was used to calculate the corrosion rate, r:
(2)
Corrosion rate, r= C×EW×icorrnρ
Where EW is the equivalent weight (g/mol), h is the number of electrons involved, r is density of alloy (g/cm3) and C is constant, 0.00327 if corrosion rate is in mm/year [7].
As can be seen in Fig. 4(c) and (d), Cu-Sn-Zn alloy produces a well-covered surface with coarse grain structure, while Cu-Sn-Zn alloy produced with 5,5-DMH as complexing agent, gave an agglomerate of dendrite small pores resulted from hydrogen evolution [8].
Fig. 6 X-ray diffraction patterns of Cu-Sn-Zn alloy produced via electroplating using different complexing agent on carbon substrate Fig. 7 Relationship between microhardness and crystallite (grain) size of Cu-Sn-Zn in the effect of different complexing agent Microhardness analysis.
It also can be seen that, the larger the crystallite grain size gave the higher value of microhardness.
The results exhibit that, Cu-Sn-Zn alloy produced in the presence of sodium formate as complexing agent exhibits the greater grain size (33.0 hm), gives the highest microhardness value (517 HV), which is almost five folds higher than microhardness value obtained for substrate (control).
As can be seen in Fig. 4(c) and (d), Cu-Sn-Zn alloy produces a well-covered surface with coarse grain structure, while Cu-Sn-Zn alloy produced with 5,5-DMH as complexing agent, gave an agglomerate of dendrite small pores resulted from hydrogen evolution [8].
Fig. 6 X-ray diffraction patterns of Cu-Sn-Zn alloy produced via electroplating using different complexing agent on carbon substrate Fig. 7 Relationship between microhardness and crystallite (grain) size of Cu-Sn-Zn in the effect of different complexing agent Microhardness analysis.
It also can be seen that, the larger the crystallite grain size gave the higher value of microhardness.
The results exhibit that, Cu-Sn-Zn alloy produced in the presence of sodium formate as complexing agent exhibits the greater grain size (33.0 hm), gives the highest microhardness value (517 HV), which is almost five folds higher than microhardness value obtained for substrate (control).
Online since: March 2024
Authors: Can Li, Yong Li, Xiao Xing Li, De Xin Zhang, Imran Sardar Muhammad, Yue Liu
It can be seen that the volume fraction of equiaxed α grains increases significantly after DB process.
The dynamic material model theory indicates that if the energy dissipation rate is small, the energy proportion of the corresponding microstructure evolution in the thermal deformation is small [16], so the corresponding deformation grains are less.
N is the total number of data.
Zhang, Hot deformation behavior and strain compensation constitutive model of equiaxed fine grain diffusion-welded micro-duplex TC4 titanium alloy, Chinese Journal of Aeronautics. 36(2023) 510–522
Liang, Influence of grain size on high-temperature compression flow behaviors of TC4 titanium alloy, Material Science and Technology. 18(2010) 302–306
The dynamic material model theory indicates that if the energy dissipation rate is small, the energy proportion of the corresponding microstructure evolution in the thermal deformation is small [16], so the corresponding deformation grains are less.
N is the total number of data.
Zhang, Hot deformation behavior and strain compensation constitutive model of equiaxed fine grain diffusion-welded micro-duplex TC4 titanium alloy, Chinese Journal of Aeronautics. 36(2023) 510–522
Liang, Influence of grain size on high-temperature compression flow behaviors of TC4 titanium alloy, Material Science and Technology. 18(2010) 302–306