Search results

Evolution of the discharge capacity of the Mg20Ni6M4 (M=Co, Cu) alloys with the cycle number: (a) M=Co, (b) M=Cu Figure 3 depicts the cycle number dependence of the discharge capacities of the Mg20Ni6M4 (M=Co, Cu) alloys.
The enhanced discharge capacities of the alloys are ascribed to the refined grain by the melt spinning in the light of the grain boundaries possessing the distribution of the maximum hydrogen concentration [6].
Figure 5 shows the cycle number dependence of the SN Fig.5.
The grain refining consequentially weakens the anti-corrosion capability of the alloy due to the fact that intercrystalline corrosion is inevitable.
Semilogarithmic curves of anodic current vs. time responses of the Mg20Ni6M4 (M=Co, Cu) alloys: (a) M=Co, (b) M=Cu spinning is ascribed to the refinement of the grains of the alloys due to that the huge number of the grain boundaries available in the nanocrystalline materials provide easy pathways for hydrogen diffusion and accelerate the hydrogen absorbing/desorbing process.

For the maximum (m3/s) we get and According to [1] the designed diameter of depositing sand grain is assumed and for which hydraulic size and , respectively.
Having m3/с m/сmm/сmm/с, to a conclusion can be arrived that actual length of sand traps is grater than their optimal length, and on the bottom not only sand grains of diameter smaller than designed one are settled, but also do organic substances.
The problem can be solved without changing , but in that case it is necessary to reduce the number of sand traps.
The number of acting sand traps is determined by maximum flow of wastewater, for , to which the hydraulic size corresponds when [1].
For the design diameter (d3) of a settled sand grain and actual length of the sand trap (Ls) , the capacity of one sand trap () is determined by the formula [1]

A large number of investigations have focused on introducing SiC and Si3N4 (i.e. gas turbines, stators, etc.) for stringent elevated temperature applications.
(b) [0 1 0] SAED diffraction pattern from a mullite grain in the coating.
The majority of the coating was found to be composed of crystalline grains of columnar morphology.
Mullite, with a space group of Pbam (space group number 55), is a derivative structure of sillimanite (Al2O3•SiO2) [12].
(b) [2 1 4] SAED pattern of mullite from one of the equiaxed grains.

The grain sizes increased with increasing Nb content.
A pseudo-perovskite layer (Am-1BmO3m+1) is sandwiched between the fuorite type sheets (Bi2O2) 2+, where m and m-1 are the numbers of oxygen octahedrals and pseudo-perovskite units in a layer, respectively.
In addition, with the increase of the Nb content, the intensity of (0010) diffraction peak becomes weak, indicating that the orientation of crystalline grain the along c axis becomes weak.
The grain size becomes larger with the increase of Nb in the SBTN.
The grain size of SBTN increases with the increase of the Nb content.

Figure 3 shows the forces resulted from grinding with a coarse grain corundum wheel.
It can be demonstrated that forces reduce as compared to the case of grinding with fine grain wheels.
In the case of grinding with high porosity and coarse grain wheels, the number of the active grains per unit area decreases that results in lower grinding forces.
In the case of conventional wheel, the coarse grain wheel is less prone to chip loading in comparison with the fine grain wheels due to the more gaps between the grains.
With similar reason, in the case of corundum wheels, coarse grains induce higher roughness than fine grains.

In Coated abrasive belt grinding abrasive grains have to withstand higher mechanical stresses for a longer time.
Under these conditions, abrasive grains are worn quickly or can be extracted from the bonding phase.
At inital stage of grinding the rapid drop charasterstic of the loss of the high sharp grains[8-9]. 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 Time in min Belt wear in gms Figure 3 Belt wear with repect to time Figure 4 Fragmented Grains at 4 min Figure 5 Worn-out Grains at 8 th min Mag-500X Mag 100X Since the wear at 4 min are influenced by the grinding pressure, the flexibility of the product does not able to differentiate process.
As the grinding operation continues, the grain height gradually decreases and the number of worn flats increases steadily.The toughness and type of workpiece decides wear the pattern.
Each grain should remain in the coating until it becomes too dull, when it would be fractured or dislodged from the coating, exposing fresh sharp cutting edges.

The sample is a grain-refined Al-5.9wt%Cu alloy.
Besides the coalescence of grains under the piston, the result of grain sliding is observed caused by the shear stress concentration in this region [8].
Such strain concentration is caused by the downward movement of the grains under the piston and the associated upward movement of the grains around the piston.
This analysis was performed using wavelengths dispersive X-ray spectroscopy with Al and Cu standards and atomic number, absorption, and fluorescence correction.
This problem would probably be relieved if the sample was larger, i.e., if the sample contained a larger number of grains, with the additional advantage that the solute distribution in such a large sample could easily be measured by mass spectroscopy.

The chemical compositions were obtained in the areas of 400×400 μm (further referred as the average composition) and in austenite grains.
Chromium carbide is located in the boundaries and triple junctions of austenite grains (figs. 2a–2e, rounded with white ovals).
The number and the size of titanium carbide coarse particles in austenite decrease significantly.
Red arrows indicate TiC phase in grain boundaries of austenite.
Black and red arrows indicate the coarse TiC particles and TiC phase in grain boundaries of austenite.

Chemical etching can produce metallographic contrast by preferential etching of individual grain orientations, where grains with a particular orientation may be more attacked.
Individual grains are etched in the form of steps which have a different orientation in each grain according to the lattice arrangement.
The more the angle of reflection approaches a right angle, the brighter the grain [1].
Numbers represent sample numbers, magnification 200×, sample center.
The vertical direction represents the sample number.

When the atomic number growth (from Dy to Lu) the parameter a of pyrochlore structure decreases (Fig.1).
As can be seen the grain size for these samples is of about 1-10 µm at the 96% of relative density [6].
One can see that these samples have lower conductivity, probably due to a small grain size and a higher grain boundary concentration.
The combination of the total conductivity measurements during reoxidation and Hebb-Wagner ion-blocking method were used to evaluate the ionic transport numbers.
Ionic transport numbers dependence on oxygen partial pressure for Er2,096Ti1,904O6,952, sintered at 1600ºC, obtained at 700 o C and 1000 oC.