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With this method, only the twinning marks and grain boundaries are visible [24].
It is important to note that type of abrasive particles of the wheel, its size and the space between grains, the type of binder, and the strength of wheel are important factors in selection of abrasive wheel [25].
The coefficient of variation is a dimensionless number that is defined as the ratio of the standard deviation (S) to the mean (W ) [13, 26]: V S C W = , (3) () 2 1 1 n i i WW S n = − = − ∑ n=5 for these Tests, (4) () 1 n i i w W n == ∑ . (5) here iW is the ith observed weight loss value, n is the number of repeats of a test (observations) that equal to 5 in this research.

Journal Title and Volume Number (to be inserted by the publisher) 3 A system designed and constructed in the authors' laboratory was used for magnetic measurements of the ELC steel [12].
The optical microstructural observations carried out after these long low temperature annealings have revealed the initial deformed grains elongated on the rolling direction, without any indication of recrystallization.
a) b) b) a) Journal Title and Volume Number (to be inserted by the publisher) 5 The increase in the apparent activation energy with increasing amount of recovery is consistent with the assumption that the most severely deformed regions, where the stored energy is the highest, and therefore the activation energy is the lowest, recover first [10].
Byrne, Ch 3, Recovery in: Recovery, recrystallization and grain growth, (The Macmillan Co., New York, 1965), p. 37

For partially exchanged samples, the ratio between the integrated Raman intensity of the D-stretching region and the H+D-stretching regions is a good measure for the local deuterium fraction x in a particular grain.[5] The x values obtained from the Raman spectra are indicated in the figure.
This indicates that the number of BD4 units decreases in the material, and the absence of shift confirms that the stretching modes are molecular vibrations, only weakly influenced by the surrounding lattice.
We show in the following that these modes arise from the symmetric stretching of partially H-exchanged BH4-nDn units, and label them n1 (BH4-nDn), with n = 1…, 4 the number of D atoms in the unit.
In addition to intrinsic, thermally induced vacancies, extrinsic defects might play an important role: (impurities, vacancy complexes, dislocations, grain boundaries etc.).

Results From the microstructure analysis it can be seen that the grain size in case of hot pressed Al6061 is about 20…40 µm which is in accordance with the raw Al6061 powder grain size (mean size 45 µm).
Therefore a more wear resistant indenter e.g hardmetal should be used when testing the surface fatigue of Al-MMCs reinforced with CNT-s The materials ability to withstand repeated contact pressure is diminished by increasing number of cycles.
In all cases the mean contact pressure pm decreases with the increasing number of cycles N.

c) the stage of forming - particles deform, boundaries between grains are developing and the number of pores reduces.
The pores are separated by grain boundary.
The matrix of partial derivatives of the state vector The Mpdx is formed of: - the state vector x(nx1), having a number of (n) lines, equal to the order (PDE); - the vector of partial derivatives of the state vector xT (Nx1), with respect to variable (t); - the matrix of partial derivatives of the state vector xS (nxM), with respect to variable (s); - the matrix of partial derivatives of the state vector xTS (NxM), with respect to variables (t) and (s); Following the matrix of partial derivatives of the state vector Mpdx is a square matrix, size Mpdx (7x7).

The number of pores and cracks is increased with increasing the content of glass microspheres.
It is believed that the glass microspheres situated on the grain boundaries disorder the lattice structures of the Bi-Sb-based alloys, causing a decrease in carrier mobility [14,15].
Using the Wiedemann–Franz law and assuming the Lorenz number to be 2.45 ×10−8 WΩ/K2, we calculated the lattice thermal conductivity by subtracting the electrical contribution from the total thermal conductivity at 80 K.
The reason is that the large defects caused by glass microspheres situated on the grain boundaries and scatter the phonons.

In any case, it is necessary to sensitively modify the method of selecting the place of taking samples from individual structural elements and their number with respect to the character of the evaluated structure.
A quite fundamental disadvantage of this cement is, however, the fact that the occurring hydration products are unstable under common atmospheric conditions and their “conversion” occurs (great attention is paid to this issue in a number of publications; therefore it is not described in detail here).
At the approximate temperature range 700°C to 820°C, a decomposition of the fine-grain calcium carbonate (i.e. vaterite and aragonite) occurs.
At the temperature interval of ca. 820°C to 940°C, a dissociation of the coarse-grain calcium carbonate (mainly calcite) occurs.

A large number of studies have shown that[10-12]the quantities, morphology and distribution of α-phase and β-phase have a great influence on alloy corrosion resistance property.
Alloy has good corrosion resistance property if the β-phase has large quantity and continuous uniform distribute in α-phase grain boundary; It can restrain corrosion extend from one α grain to the other one if the β-phase has reticular structure and the larger volume fraction.
The corrosion situation of AZ91DSm1.0-2 is similar to the AZ91DSm1.0-1, the differences are when AZ91DSm1. 0-2 just immerse in 5% NaCl, there are air bubbles as soon as, the quantities of bubbles are rapidly increase with the increasing of immersing time, and accompany by bursts sound, a large number of flocculent white corrosion products soon emerge in NaCl solution.

A number of rapid prototyping techniques are available, which differ in a material to be used and a way to form an article.
SLM-based manufacturing of a high-quality article is associated with a number of complex and ambivalent physical phenomena despite advantages of additive technologies.
Materials and Methods A powdered copper material with flake-shaped particles was used in experiments; Table 1 gives its grain size distribution.
Table 1 – Grain size distribution, % dimensions of particles <100 [µm] 99.5-100 <71 [µm] 90-100 <45 [µm] 65-80 Non-contact optic microscope LEXT OLS 4100 (OLYMPUS) was employed to examine roughness of the surface layer in a 3D system of coordinates, Fig. 1.

With the increase of undercooling, the cellular growth morphology is more obvious, the structure distribution is more uniform, and the grains are further refined.
Within this range of undercooling, Au phase will nucleate and grow preferentially as primary phase, so a large number of long rod-shaped dendrites appear in the solidified structure.
There are a large number of coarse dendrites in solidified structure when the undercooling is greater than 56 K.
Yang, Non-equilibrium transformation kinetics and primary grain size distribution in the rapid solidification of Fe–B hypereutectic alloy.