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Grain boundaries corrosion and transgranular local corrosion were found in Fig. 1.This was caused by pearlite and martensite formed in cast structure of stainless steel.
General corrosion and severe cracking of grain boundary were also found on the surface of the specimens.
This result was supported by the SEM macromorphologies from which the evident ravine could be seen, and it indicated the grain boundary bonding had disappeared.
Secondly, though the grain boundary corrosion morphology in the sulfuric acid (Figure 1), it can be found that the intergranular corrosion of the two materials are mainly due to the corrosion of the lath martensite at high stresses in grain boundary, which is often due to the high stress area turning into anode that can be corroded easily, and because of a small number non-ferrite structures in grain boundary, boron-containing sample is less corrosive.
In addition, part of lamellar pearlite and interphase precipitate tissue of samples with boron distributed along the grain boundaries, which resulted in occurrence of pitting along the grain boundaries, promoted the intergranular corrosion tendency of containing-boron sample in the chloride medium.

CS(nm) SnS (Pure) 31.72 2.817 (111) 0.606 14.23 SnS:Cu(0.01) 31.72 2.817 (111) 0.511 16.88 SnS:Cu(0.03) 31.72 2.817 (111) 0.459 18.79 SnS:Cu(0.05) 31.72 2.817 (111) 0.379 22.75 AFM shown in Fig.(3) Morphology of SnS films have minor circular grains, more numbers of grain boundaries.
The SnS:Cu film has a great surface, collect crystal periodic grains.
It is evident that the size of the grain increases with growth in doping to 0.05 of Cu.
Grain size and its roughness values of the pure and doped thin films are shown in Table 3.
Grain size and roughness for pure SnS thin film and doped Cu (0.01, 0.03 and 0.05).

It was found that the biggest grain sizes obtain from sample 14, which is 58.87nm produces a high crystal quality, among others.
XRD data shows that it has a larger grain size with low lattice strain.
These numbers of properties make ZnO as a one of promising semiconductor materials to use in many scientific and industrials areas such as piezoelectric transducers, optical waveguides, acousto-optic media, conductive gas sensors, and varistors [13].
To obtain the detailed structure information, the grain size along c-axis was calculated according to the Scherrer formula [16].
From the analysis of XRD data, it shows that the sample has a larger grain size, which indicates as a best crystallinity among others.

. %) and a small addition of titanium is added for grain growth control in the heat affected zone of welds [3].
Austenitizing temperature of 970°C was too low for dissolution of both primary and secondary titanium rich MX particles and fine secondary MX particles (ca 100 nm) inhibited austenite grain size growth.
All austenitic lamellae inside one prior austenite grain had the identical crystallographic orientation.
Fig. 4a shows a network of precipitates along a prior austenite grain boundary.
Diffraction patterns of Laves phase revealed pronounced “streaking” due to a number of defects on the basal plane (001), Fig. 6.

These results suggest that the corrosion resistance of these ceramics is strongly affected by the presence of grain boundary phase.
After removing this corrosion product by ultrasonic cleaning in redistilled water, a number of corrosion pits were clearly observed on the substrate surface.
Although traces of grain exfoliation are recognized, the rest of the surface looks virtually intact.
On the other hand, intergranular corrosion due to selective dissolution of grain boundary phase was observed for SiC sintered with B and C
Its corrosion morphology was selective dissolution of impurities segregated over grain boundaries.

However, consolidation of conventional microcrystalline W powder of 3 – 4 µm average grain size is difficult [2-4].
Table 1 Nominal compositions of alloys selected; W crystallite size after milling for 5 h; sintered density and grain size of as sintered samples.
The grain size of the sintered W0.5Cr0.5 and (W0.5Cr0.5)90Nb10 alloys were 7.30 to 6.45 µm, respectively.
This is marginally lower than the grain size of pure W (10.88 µm) sintered under similar conditions (Table 1).
Acknowledgement The authors wish to express their thanks to the Defence Research Development Organisation (DRDO), India, for the financial support under the project number ERIP/ER/0700335/M/01/1014 dt.22.11.2007.

Thus the forming pressure of HPS is only 1/10 of the cold-pressing sintering, it also can reduce the sintering temperature and shorten the sintering time, and thereby resist the growth of grain and obtain the products with fine grains, high density and good mechanical and electrical properties.
It showed that a full grain refinement of the composite powders was produced in MA, and the particle size distribution was uniform.
As can be seen from the graph, grain boundary of sintered alloy were clear and uniform and grain was tiny to 2µm.
According to experience of sintering thermodynamics, when sintering pressure was very low, the pore numbers of sintered body will be increased.
By setting reasonable process parameters, the sintered plate showed good microstructure and fine grains.

In the Table 1 w - Fmax is the bending deflection measured in the impact of maximal loading force, x is the mean number, s is the mean square error, ν is the coefficient of variation, min. and max. are the minimal and the maximal measured values.
For simplification, wood may be reasonably modeled as orthotropic material with symmetric properties in directions perpendicular to the grain.
Due to measuring had been made in the grain direction, some values were reduced.
Cracks perpendicular to the grain was first observed during the loading (Fig. 6).
Fig. 6 Cracks perpendicular to the grain in FEM model The ATENA cementitious material model does not assign satisfactory behaviour (Fig. 7).

The substitution of M (M=Cu, Co) for Ni results in forming secondary phases Mg2Cu and MgCo2 without changing the Mg2Ni major phase, and such substitution renders the notable refinement of the grains of the as-cast alloys.
The ameliorated hydriding kinetics is undoubtedly associated with the refinement of the grains generated by the melt spinning.
Consequently, high densities of crystal defects such as dislocations, stacking faults and grain boundaries are introduced as shown in Fig. 5.
The large number of interfaces and grain boundaries available in the nanocrystalline materials provide easy pathways for hydrogen diffusion and accelerates the hydrogen absorbing- Fig. 5 The crystal defects in the as-spun (30 m/s) Mg20Ni6Cu4 alloy taken by HRTEM: (a) Stacking fault denoted as A; (b) Twin grain boundary denoted as B, Dislocations denoted as C and sub-grain boundaries denoted as D desorbing process [8].

The sample consists in non-uniform large grains ranging from a few micrometers up to tens of micrometers.
The grains have octahedral irregular morphology.
The grains diameters are in micrometers range.
Practically, the ceramic sample consisting in large grains is fractured resulting particles with different diameters.
Acknowledgement This work was supported by CNCSIS – UEFISCSU, project number PN-II-ID-PCE-2012-4-0632.