Search results

Cutting performance of a grinding wheel is impaired with operating time due to many factors such as abrasive grain blunting and working surface glazing.
A number of works have been devoted to studying these processes [1, 2, 9, 13, 14].
The glazed diamond wheel’s surface is not capable of working since this glazed layer covers the working surface fully and thus prevents replacement of worn grains for fresh ones.
Such an approach allows more uniform dissolution of metal over the total contact area and generation of only negligible defects as a result of electric breakdown erosion and the worn grain removal.
Nakagawa, Analysis of mirror surface generation of hard and brittle materials by ELID (electrolytic in-process dressing) grinding with superfine grain metallic bond wheels, Ann.

We predict, a-C films might deform structure with dopant of nitrogen to provide excess of electron thereby reduce the number of defect of films.
The surface roughness of a-C:N from 0 mL/min to 200 mL/min are 6.419 nm, 2.540 nm, 5.652 nm, 11.08 nm, 2.979 nm, and 4.947 nm, respectively while the average grain sizes are 0.8325 μm2, 0.7377 μm2, 0.4994 μm2, 0.5174 μm2, 0.288 μm2, and 0.483 μm2, respectively.
In comparison with conductivity and average grain size, decreases in conductivity film might be due to high surface roughness, the high average grain size and low carrier concentration of the a-C at undoped sample (0 mL/min).
The relation of average grain size and surface roughness with carrier concentration and carrier mobility in determining the value of electrical conductivity we previously reported [9-10].

However, this field is still very attractive for further research work because of a large number of steel compositions for which one can observe interesting material properties and because of many potential applications of thixoforming of steel.
During heating, when the solidus temperature is exceeded, the liquid phase penetrates boundaries of recrystallized grains, causing the fragmentation of the solid phase resulting in obtaining a globular microstructure.
The structures show solid grains surrounded by traces of the liquid matrix.
One can observe that a higher temperature gives more traces of the liquid fraction both inside solid grains and along their boundaries.
Courtois: Fine grained metal composition, US Patent no. 4,415,374, (30 March, 1982) [8] M.Z.

The cohesion of the grains with the cement paste was high at those temperatures, which caused grain cracks in numerous sites.
The fracture surfaces tended to be more tortuous and less cracks across the grains were observed, pulling from the grains out of the cement paste occurred.
A complete load-displacement curve can represent a number of findings: the initial stiffness, the ultimate load capacity, the displacements at cracking and failure, hardening and softening properties, etc.

Etching of the substrate surfaces with thermal effect revealed the grain boundaries.
Angle 2θ Wave Number (cm-1) Figure 4: Sem photography of C4 sample.
Grain size measured with the intercept method.
The grain size of the C4 sample is smaller than the pure HA grain size of 0.56 µm.

In a solar cell, an injected electron has to transport across a large number of colloidal particles and grain boundaries.
The aggregates individual grains are difficult to be identified precisely owing to the image overlaps which restrains the electron transfer and results in reducing the short-circuit photocurrent as well as the open-circuit voltage.
The surface of the TiO2 film is nanoporous and the size of the TiO2 grain is about 20 nm.
The main factors, affecting the photoelectric property of dye-sensitized TiO2 ceramic films, are the size of TiO2 grain, the uniform degree and the continuity of the thin films.

Srivatsan et al. [9] also reported that the formation of TiB2 effectively inhibited the B4C grain growth.
The TiB2 addition and smaller grain size were considered the major influencing factors on the increase of the flexural strength.
The fracture Table 1 Mechanical properties of the B4C-Al and B4C-TiB2-Al composites Composite Hardness (HRA) Flexural strength / MPa TiB2 Fracture toughness / (MPa·m1/2) B4C-Al 82.2 ± 0.37 362 ± 6.1 5.8 ± 0.12 B4C-TiB2-Al 80.3 ± 0.65 599 ± 5.9 7.8 ± 0.11 toughness was improved significantly due to the B4C grain refinement and more ductile aluminum existing.
The TEM images showed a number of striations, which were confirmed to be twins with twin planeas shown in Fig. 4.
Besides that, the improvement of fracture toughness was well related to the B4C grain refinement, the difference in thermal expansion between the B4C matrix and the TiB2 particle, and the existence of the twins in B4C matrix.

Furthermore, such substitution incurs the notable refinement of the grains of the as-cast alloys.
The superior hydrogen absorption kinetics is undoubtedly associated with the refinement of the grains produced by the melt spinning.
Consequently, high densities of crystal defects such as dislocations, stacking faults and grain boundaries are introduced.
The large number of interfaces and grain boundaries available in the nanocrystalline materials provide easy pathways for hydrogen diffusion and accelerates the hydrogen absorbing/desorbing process [9].

He described it thusly: The folding pattern in the metal of the lower third is a medium sized board-grain (itame), and in the upper third there are some features that are almost a whorl pattern (mokume).
The burnishing on the upper portion of the blade is very well done and may be the cause of some straight grain openings.
Blade cross section unetched (left) and etched with nital (right) The blade cross section and the wedge near the hilt show an identical construction: an edge of untempered martensite with a body of highly variable carbon content and grain size.
But, during this time of extended warfare, Bizen became known not just for the fine blades produced by highly skilled smiths, but also for cheap swords manufactured in high numbers to supply the various armies of the day.
The steel’s grain, where visible is straight.

The sintering process is the compaction of material grains under thermal stress.
If the limestone or used fuels contain more sodium, the grains can be sintered more slowly.
On the opposite, silica, alumina, and iron oxides can increase the grain sintering rate [2].
Sample B is bioclastic lime-mudstone to wackestone with fine-grained matrix with abundant very small peloids, which are densely packed and exhibiting a clotted fabric.
Acknowledgements This work was financially supported by BUT student research project number: FAST-J-20-6520 “Influence of genesis and type of limestone on the process of decarbonation and the CaO sintering process” References [1] Best Available Techniques (BAT) Reference Document for the Production of Cement, Lime and Magnesium Oxide.