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The influence of covered area, number of measurement points and grains on the validity of texture analysis are also discussed.
Thus, the number of grains probed and the total covered area should be considered for the statistical reliability of EBSD based texture analysis.
CI) of the austenite phase, number of austenite grains and number of points included of each map in comparison are shown in Table 1.
The number of probed grains depends on the step size and average grain size of the material for scans with the same total number of measurement points.
These studies suggested the number of probed grains to be in the range of 200 – 3000 for reliable EBSD based texture analysis.

The result shows that the Al-3Ti-0.5B master alloy which was prepared by adding mixture of Ti sponge and KBF4 power into molten aluminum contains a large number of granular TiB2 phase and blocky TiAl3 phase.
Addition of grain refiners is the most common and effective method for refining the grain structure during the solidification process [1-3].
Compared with B alloy, the number of TiB2 particles in A alloy is more.
Figure 5.a) shows that commercial purity Al without grain refiner exhibits coarse equiaxed grains and columnar grains.
The macrostructure of Al is composed of fine equiaxed grains after the addition of grain refiner as shown in Figure 5.b) and Figure 5.c) respectively.

There are number of refinement mechanisms proposed over the years for grain refinement.
The cavitation induced dendrite fragmentation hypothesis assumes that the shock waves generated from the collapse of bubbles lead to fragmentation of dendrites, which are redistributed through acoustic streaming, thereby increasing the number of crystals.
When ultrasonic intensity is increased to 4 kW/cm2 increased grain refinement is observed and grain size is reduced further to 17 μm.
This hypothesis assumes that the shock waves generated from the collapse of cavitation bubbles cause fragmentation of the dendrites, which are then redistributed through acoustic streaming, thereby increasing the number of crystals and hence refining the grain size.
As a result of grain refinement, the grain boundary area is increased.

The larger grain size, the smaller crack growth rate, though the static strength was decreased with increase in grain size.
The influence of grain size on the crack growth is complex.
For example, ultra fine-grained carbon steels have an excellent crack growth resistance, though the resistance is not influenced by grain size in conventional grained steels [2].
The relation between the logarithms of a crack length and the number of cycle can be approximated by a straight line, when the crack length is small.
The larger grain size, the smaller crack growth rate, though the static strength was decreased with increase in grain size inversely.

During the past few decades, A Large number of research on particle breakage of coarse-grained soil have been carried out by many scholars abroad, and have obtained certain achievements[2-8].
Size grading curve of coarse-grained soil Table 1.
The particle breakage characteristics of coarse-grained soil is studied.
In-situ compaction of coarse-grained materials[M].
Study on wetting breakage of coarse-grained mate[J].

The optimized relaxing time on grain refinement is 60 s.
The linear intercept method was used to measure mean austenite grain diameters.
The austenite grain size becomes smaller with the decrease of reheating temperature.
A small grain sized austenite has a relatively large number density of grain boundary nucleation sites so bainite dominates the microstructure, whereas a relatively large number density of intragranular nucleation sites leads to a microstructure consisting of predominant acicular ferrite [13].
It is therefore proposed that lath-like or plate-like acicular ferrite grains formed earlier effectively divide prior austenite grains into smaller and separate regions.

In order to clarify the difference between the grain boundaries in ARB-Cu and equilibrium boundaries, calculated atomic structure of symmetric tilt grain boundaries with <110> common axis (<110> symmetric tilt grain boundary; <110> STGB) in Cu were used.
Therefore, it is expected that the mechanical properties of the ARB processed material having numerous number of grain boundaries are governed by the atomic structure of the boundaries.
However, the atomic structure of the grain boundaries in the ultrafine grained materials fabricated by the SPD has been rarely studied.
Furthermore, in order to compare the grain boundaries in the ARB-Cu with equilibrium grain boundaries, the MD simulated grain boundary structures of copper [4] were used.
The misorientation angle between adjacent grains was about 14˚.

The number of components required defines the order of the tensor since the kinetic coupling occurs between all recrystallizing and all deformed components.
Firstly, it reduces the number of deformed and newly formed recrystallized orientations to only a small number of discrete components.
The number of discrete texture components typically required for instance for the case of low carbon steel sheets amounts to 5-10.
It is also possible to increase the number of components for higher precision.
In the model essentially three types of grain boundaries have been used, namely, low angle grain boundaries which have a low mobility, high angle grain boundaries which have a larger mobility, and one type of special grain boundary (27°<110>) with a very high mobility.

Both in the two alloys, surface relief was formed at most grain boundaries by the stretching, while hydrogen evolution was observed at some grain boundaries.
A number of white particles were observed at some grain boundaries and slip lines of each specimen.
The larger the tensile deformation amount, the greater the number of grain boundaries with hydrogen evolution in Al-Mg specimens.
Both in the two alloys, surface relief was formed at most grain boundaries by the stretching, while hydrogen evolution was observed at some grain boundaries.
In a peak-aged Al-Zn-Mg alloy, precipitate free zones (PFZs) exist along grain boundaries and deform more easily than the interior of the grains [6] and also than the zones near the grain boundaries in the Al-Mg alloy that have larger numbers of solute atoms.

Refining prior austenite grain size is the prerequisite for fine ferrite grain, because of the ferritic nucleation on austenite grain boundaries.
These precipitates pin the austenite grain boundaries and inhibit the grain growth of austenite and thus keeping the grain size fine.
The grain size was then determined from this number.
Prior Austenite Grain Size.
So there are no second phase particles to inhibit grain growth of austenite grains.