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Grain undeformed chip thickness mh .
Grain undeformed chip thickness mh is usually calculated by the following expressions: 1 2 1 2 2 cos cos 2 2 1 cos we s w s s m se e s s w v a v a d h L L v d v d d α α β          ⋅ = = ⋅ +                  (8) The maximum grain undeformed chip thickness occurs at the maximum deep of the wheel.
Comparing with it, tangent point-grinding angle α makes the maximum grain undeformed chip thickness mh thinner, and the bigger α is, the thinner mh is.
Moreover, every point deep on the generatrix of the wheel is decreasing, which makes the average undeformed chip thickness mh smaller than the maximum grain undeformed chip thickness mh .
It makes the number of cutting points per second becoming larger, the grain undeformed chip thickness mh becoming thinner, the geometrical contact length cl becoming longer and the grinding force becoming smaller.

Massart and subsequent inhibition of the grain growth by covering them with dextran [1] or other shells.
Analysis of the chemical composition of the layers deposited from colloidal solutions by XRD and Raman spectroscopy showed an increase in the peaks’ width and the shift of the bands corresponding to the iron oxide grains’ dimensions less than 10 nm [2,3].
Assuming that α and β are relative number of magnetic moments oriented towards or against external field H accordingly.
Probably, colloidal particles contain nanometer sized iron oxide grains corresponding chemically inhomogeneous heterophase systems.
Alternatively, iron oxide grains consist of magnetite/maghemite core covered by outer layers of hematite and goethite/hydrogoethite so integral magnetic properties are significantly weaker in comparison to pure magnetite or maghemite.

The grain boundary has very high energy and certain tension effect, so purities can enrich here easily.
As a result, in the anodization process, the growth of pores in the boundary is different from that inside the grains.
Obviously, the area of regularly-arranged pores was inside the same grain.
Consequently, the grains grew larger; the number of grains decreased; the area of grain boundary reduced.

Oxygen atoms seemed to have attacked along the grain boundaries and the lath boundaries and formed oxide CrO3 along the boundaries.
A smooth interface between the outermost and the next inner layers seem to be TM MA956: trade name of SMC (Special Metals Corporation) the original surface of the specimen because the next inner layer shows the original microstructural features, like the grain boundaries, lath boundaries, and precipitates.
An internal oxidation zone, which seems to penetrate along the grain boundaries and lath boundaries, was also observed next to the matrix.
Cross sectional TEM micrograph of oxide scale layers on T91 specimen after 200 hr in a supercritical water (627 o C/25MPa); numbers on the micrograph indicate the EDS point analyses The original specimen surface seems to [at%] Fe Cr Si Mn O 1 Bal. 4.54 0.16 1.08 49.54 2 Bal. 6.21 0.19 0.88 50.03 3 Bal. 10.35 1.09 0.463 52.35 10 µµµµm correspond to the interface between the outermost oxide layer and the next one, i.e. between the layer of Fe3O4 and that of (Fe,Cr)3O4.
In the latter the original grain boundaries, lath boundaries with precipitates are shown.

MgO-ZrO2 brick has the defect of poor thermal shock resistance in use, the incorporation of MgO-rich spinel into MgO-ZrO2 brick significantly improved both thermal shock resistance and hot modulus of rupture because of the formation of eutectoid structure of grain-refining spinel and zirconia, which also improved structure spalling resistance because air permeability was decreased to 5% of MgO-ZrO2 brick.
It is found in table 2 that apparent porosity and air permeability of MgO-ZrO2(11wt%)brick (MZ) is far less than that of rebonded MgO-Cr2O3 (26wt%)brick(RMC), air permeability is the eigenvalue of degree that air penetrates material under a certain pressure difference, which is determined by the size and number of interconnected pores.
They show that the distribution of ZrO2 changes radically, most of ZrO2 is distributed in the inner of spinel rather than the grain boundary of MgO and ZrO2 (Fig.2(c)), the grain size of ZrO2 is refined significantly, it is about 2um and decreased to about 1/15 of the grain size in MZ, and the grain refinement is avail to improve strength [6-7].
The 1600℃and 1800℃ isothermal section of MgO-Al2O3-ZrO2 ternary phase diagram are shown in Fig.5, in the temperature range 1600 to 1700℃, a ternary compound Mg5+xAl2.4-xZr1.7+0.25xO12 (-0.4 ≤ x ≤0.4) becomes stable in the MgO-rich part of the system [9]，when the ternary compound is hot annealed at or slightly below 1600℃, it decomposes within about 2h to the metastable assemblage MgO + c-ZrO2 + Al2O3, which only subsequently is transformed to MgO + spinel + c-ZrO2, so the ultra-fine grained spinel and ZrO2 eutectoid structure is generated, which can help improve high temperature strength and thermal shock resistance remarkably [6-7].
With the addition of MgO-rich spinel into MZ, marked improvements were observed on thermal shock resistance, hot modulus of rupture values by factors of 5, 1.5, respectively, and air permeability was decreased to 5% of MZ, which can improve structure spalling resistance significantly also, all this good properties should owe to the formation of the ultra-fine grained spinel and ZrO2 eutectoid structure.

This is a convincing demonstration of the attractiveness of the area of bulk ultrafine grained and nanostructured materials produced by severe plastic deformation to a large community of researchers and engineers.
As a matter of fact, this community is growing, and the total number of articles in these proceedings (175) is larger than in the proceedings of any previous NanoSPD conference.
This refers to all aspects of NanoSPD, including our understanding of the mechanisms underlying grain refinement by severe plastic deformation, characterisation of the properties of SPD-processed materials, improvement of processing techniques, and, finally, their applications.

The size of the matrix phase (alpha- or beta-grains) size and morphology of α+β intragranular mixture were varied using different treatments.
The first one was in single-phase α- phase state with average grain size 80 mm (c.p.Ti – Fig. 1a); the second alloy was investigated in two different microstructural conditions – lamellar (Ti64LM – Fig. 1b) and partially transformed into globular one (Ti64GL – Fig. 1c); the last alloy was taken in single-phase metastable β state with relatively Fine Grains (LCBFG – Fig. 1d) and in two-phase α+β state after Annealing (LCBAN – Fig. 1e).
In the same alloy with lamellar microstructure cracks propagated not along a grain boundary (like it take place on tension [8]), but through the edges between adjacent packets of α- lamellas (Fig. 6c).
However, like in case of tensile tests, α/β interphase boundaries play an important role in the nucleation and growth of fracturing cracks, namely, their number (density) and shape, determined by the morphology of the structure of the alpha phase.
Also, at higher magnification areas with brittle facets were found between ductile dimples (Fig. 8b), which may be associated with secondary cracking along separate β- grains’ boundaries.

All of the studied alloys showed macrostructure consisting of radially oriented columnar grains in the directions perpendicular to the casting axis.
Results and discussion After homogenization all of the studied alloys showed the macrostructure of radially oriented columnar grains that lie in the direction perpendicular to the casting axis.
The columnar grains are 0.5 mm to 5 mm long, 0.5-1.5 mm width, and about 2 mm high in the casting direction.
The grain boundary between two neighbouring martensitic plates (V1 and V2) is not flat but rather zigzag type (Fig. 2e).
Since indium has the lowest number of valence electrons so for alloys enriched in this element decreasing of Ms should be observed as a consequence of e/a descent.

In addition, there is a slight decrease in the number of Ag aggregates, associated with an increase of the spherical definition of the Ag particles shape (becoming nearly spherical) [6,21], together with a slight increase in the aggregate’s dimension on the surface (coalescence) [22, 23].
Influence of the annealing temperature on the grain size evolution of TiN (111) and Ag (111) peaks of the five representative samples.
Firstly, the zone where it can be observed grain size values varying from 17 to 19 nm for TiN (111) and from 13 to 15 nm for Ag (111).
Above 300 ºC, one can observe a different zone, where an increasing annealing temperature leads to a slight increase of the TiN grain size (although the values are still below the ones from the first zone) and a steep increase of the Ag grain size, once the free metallic silver atoms embedded in the TiN matrix easily segregate and coalesce (increasing Ag grain size) by action of the high temperatures.
Indeed, the Ag incorporation causes a decrease in the TiN matrix grain size as the segregation of the Ag grains occurs preferentially across the TiN grain boundaries, thus hindering the TiN grain size growth [2].

Schematic of “throttling” in slide gate application and controlling the flow rate of molten steel The materials used in this application need to be well designed with a number of requirements in mind.
The approach used is the employment of primarily MgO grains in a carbon containing bonding phase along with antioxidant reactive metal additives.
The number of cracks and crack opening displacements are far less in the developed magnesia-carbon material than in the oxide bonded magnesia material.
In addition, thermal expansion mismatch between the high thermal expansion MgO grains and the surrounding carbon containing matrix does not allow for a strong bond between the grains and matrix, and this accelerates grain pullout when two plates are slid against each other.
However, poor resistance to abrasion and grain pull-out was found to be the dominant limiting factor in this material.