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(a) (b) Figure 1 (a) Schematic view of the diamond face turning (b) Experimental setup of the face turning process Even though the diamond turning process introduces very little damage to the machined surface and the cutting force involved in SCD diamond face turning is relatively low, the final quality of the machined surface depends on the depth of cut and number of passes.
In the thin machined samples (samples C, D and E), the microstructures become more random, denser, and finer with the shape of the grains less elongated as compare to the bulk and thick machined sample with the average length of the grains are 52, 45 and 39m for sample C, D and E respectively.
In sample C and E some grains are observed shifted in the sense that the elongated grains are not anymore perpendicular to the machined surface.
The deformation introduces strains into the grains located in the surface and subsurface of the workpiece during chip formation.
The machining of thin sheet workpiece induced grain refinement and also generates the change of material properties from texture (grains with preferential orientation) to the less preferred orientation.

The average grain size is approximately 600 nm.
Compared with Fig. 1a), the increased annealing time resulted in the grain to coarsen (Fig. 2a) and some big grain grows up to 2.2mm in large direction.
The grain size is about 3mm.
Furthermore, a large number of parallel bands substructure inside the martensite variant can be found.
Further increasing annealing time resulted in the grain size growing up either.

This technology is used in a number of underground coal mines, rock salt mines, stone mines, etc [1-6].
At the same time, a number of studies have shown that one of the factors having a significant effect on deformation processes in a rock mass is a heterogeneous block-like (grain) structure that is necessary to take into account for modeling. [7-11].
Grain boundary sliding is accepted.
We restrict ourselves to the case, where grain and pore properties of the material are linearly elastic but have different elastic constants.
A non-Archimedean number system to characterize the structurally inhomogeneous rock behavior nearby a tunnel.

The steel plates were bent by different number of laser scans and therefore, each was bent to a different extent.
As a result, the grains in the HAZ were visibly refined.
It was however also observed that the grains are much smaller (approximate grain size is less than 3 µm) in the region immediately below the top part of the HAZ (sub-region), Fig.6.
Recrystallized grains were observed at approx. 4.2 mm below the surface.
The grain refinement with an average grain size of approximately 6 µm indicates that dynamic recrystallization occurred.

The results showed that nano additive reduces the size of TiO2 grain.
This is related to the size and morphology of TiO2 grains.
This figure shows a uniform microstructure containing TiO2 grains.
It can be seen that grain sizes decreas with the increase of the concentration of nano TiO2 powder, meaning that the nano TiO2 powder could inhibit grain growth.
According to the boundary barrier model, the breakdown voltage , Eb, for a varistor is determined by the mean number of barriers n in series multiplied by vb, that is [15] : (2) where vb is the voltage barrier at a grain boundary, which is almost a constant for different samples.

The morphology of grains, was analysed by measuring a shape factor the (4pA)/P2.
The microstructure of the base metal (Fig. 3) consists of non-dendritic primary a grains surrounded by a near-eutectic secondary phase composed of aluminium and silicon grains.
These grains get advected towards the solidifying front due to weld pool convection and drag on the grains as schematically shown in Fig. 4.
A lower thermal gradient near the edge of the meltpool and a larger PMZ width should imply a larger number of nucleation sites and thus lead to finer weldment microstructure that is also globular.
The higher width of the PMZ in the copper backing arrangement may be attributed to a greater number of loose grains, hence more nuclei, than that of the base metal, causing globular a microstructure in the FZ.

They were studied separately for localities with coarse grains and then for fine-grained ferrite near to the slab surface some 2 to 3 mm deep.
The grain size is coarser (with grain size No.2 and d = 0.177 mm) and heterogeneity of grain size is lower compared to sample No.2 from the slab part with the lower pulling rate.
The total number of measured particles was 306.
This heterogeneity in ferritic grain size originates from the heterogeneous distribution of precipitates with various average dimensions, as shown in Table 2 for the fine-grained and coarse-grained zones in the slab surface at the slower pulling rate.
Mean size 2r [nm] N-2 0.4 No.2 fine-grained ferrite 32.5 No.2 coarse-grained ferrite 41.8 R-4 0.8 No.

An austenite grain size gradient is also established with the coarsest grains forming adjacent to the fusion boundary (in the GCHAZ).
The austenite grain size (dA) decreases as the peak temperature falls, with an accompanying decline in hardenability.
The 80 of the identifying code represents BIS80, the third number is the heat input (2, 4 or 7 kJ/mm) and the last two, the plate thickness (mm).
The refined prior austenite grain size remains a structural entity within the bainitic structure (i.e. austenite grain boundaries are not obliterated as they are when aP and/or aQ are formed).
Therefore, it was proposed [3] that an austenite grain size effect occurs, as shown by Grange [8] for AISI 4340.

Some grains grow abnormally if the proportion deviate from this value and there are a lot agglomerates.
There have a large number of particles of 40-60 nm size and a few particles of 20-40nm size ,even though PEG is added as a dispersant agent.
For commercial applications, both small grain size and chemical purity is of prime importance.
When the proportion of monomer and network agent is 5:1, the size of grains is small and uniform.
The grain size is not more than 20nm and there are few agglomerates.

Besides, the grains of base metal had deformation phenomena.
Fig. 3 Testing regions Table 4 Results of hardness testing Number Results of microhardness testing Ⅰ(1～13) 13.3 396.0 214.3 181.5 169.3 417.6 574.8 Ⅱ(2～14) 16.9 344.7 204.3 157.0 220.6 486.8 532.4 2.2 Microstructure of welding joint.
The grain size of base metal was close to that of the heat-affected zone.
The grain size of base metal was smaller and the density of base metal was higher than those of heat-affected zone.
Besides, the grains of base metal had deformation phenomena.