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Powder Tape Casting Sintering Poling Heating above Tc Random Grain Texture Grain Texture Grain & Domain Texture Grain Texture Random - Random Domain Texture Random Fig. 1.
Both texture components contribute to the absolute number of spontaneous polarization vectors and ferroelastic distortions aligned in any given sample direction.
In other words, only a small absolute number of polarization vectors can be aligned in a specimen direction where the grain texture component does not provide directions of possible structural distortion; such considerations exist regardless of the domain switching fraction.
Likewise, even in a textured ceramic with nearly perfect orientation, the absolute number of polarization directions parallel to the electric field can be restricted by the domain switching fraction.
Grain Texture The tape casting process induces a grain texture with a 001 fiber symmetry axis.

Individual grains or group of grains undergo large relative rotations.
At low strain rate enhanced grain growth occurs.
Grain boundary sliding as well as grain boundary migration occurs extensively.
iv) Grain boundary orientation: The grain boundaries between adjacent matrix grains should be high energy (i.e. high angle or disordered).
vii) Mobility of grain boundaries: - Mobility of grain boundaries develops at triple points as well as at other obstructions along grain boundary.

A number of studies were carried out in the work, which included testing samples in a heat-treated state and free.
The structure includes a relatively small number of alloying elements.
The greater the indentation depth, the lower the hardness number HR.
The flat surface of the specimen was sequentially polished with various types of emery paper - first coarse-grained (M40), then medium-grained (P800; P1200), then fine-grained (P1500; P2000).
In comparison with the free state of the metal, where the structure is fine-grained, after heat treatment, the structure of the studied steel SS34 becomes homogeneous and an increase in grains is observed.

The addition of these refiners introduces a large number of particles like Al3Ti and TiB2 or TiC into Al melts.
The particles acted as nuclei of α-Al grains in Al melts promote equiaxed and fine grain structures during solidification.
In previous study [2], the role of Al3Ti and TiB2 in Al-Ti-B alloy refiner on grain refining efficiency of α-Al grain in pure Al cast has been reported.
Commercial Al-5mass%Ti alloy ingot was used as grain refiner.
Grain refinement of pure Al cast using Al-Ti alloy refiner.

Today the deep drawing process is already used to produce large numbers of small parts (diameter < 1 mm) at low costs per part.
An increasing number of grains at the surface, which are less restricted than volume grains, leads to less hardening in the surface layer and the directly adjoining grains [1, 3, 5-8]
With an increasing ratio up to ~ 0.2 (5 grains over foil thickness) the strength of a metal reduces for constant grain sizes and decreasing number of grains over the cross section if a critical material dependant value is reached (Table 2), as shown in [5-8].
In the work of [12] a number of 50 grains over the cross-section is given as a critical value influencing the flow stress of a metal.
Critical grain number depending on material Source Material Grain size [µm] Critical grain number Cu 65 5 - 7 [5-7] Cu-13 at% Al 40 10 - 15 [8] Sn and Sn alloys ~ 20 Influence of Punch Velocity on the Punch Force.

Cooling rate significantly influences the grain size as well as the grain growth kinetics.
But the number of research articles directed towards the atomistic studies of solidification of metals/alloys/composites are limited in number [2].
The embedded atom method has been extensively used to study the properties of a large number of metals.
The grain growth kinetics has been investigated keeping the system at temperature 853 K for a long duration of time.
Therefore, for a practical cooling rate of 1 K/s and a system size of few cm3, a greater number of atoms will be accumulated at a particular location to form grains at the initial stage and rearrange themselves in the later stage to form more stable structure.

However, despite efforts made over a number of years, the control of the industrial casting process remains unsatisfactory; resulting in a significant number of the components produced being rejected due to solidification defects.
These boundaries can be due to a number of different causes.
When the local undercooling is sufficient to exceed the undercoolability of the used alloy, new grains may nucleate to generate macroscopic stray grain defects [2, 3].
The CMSX6 samples reveal a prominent low tendency for stray grains.
In this case, the formation of stray grains is avoided.

However, magnesium has a hexagonal closed-packed (HCP) crystal structure with a limited number of operative slip systems at room temperature, and its formability is restricted to mild deformation.
Some grain boundary areas contain small recrystallized grains.
The annealed microstructures (Fig. 5(d),(h)) consist of equiaxed grains with relatively clear grain boundaries.
In general the grain size becomes finer with increasing number of pass and decreasing deformation temperature as shown in Fig. 6(b-d),(f-h).
In general the grain size becomes finer with increasing number of pass and decreasing deformation temperature.

But there are only a small number of reports on the microstructure of EEUSS coatings yet, and very few studies concerning the grain abrasion properties of the EEUSS coatings have been done.
Also, the liquid metals surrounding TiC grains give rise to the increased diffusion path, reduce the driving force for TiC grain growth, and prevent the sintering between TiC grains to form larger grains.
The compact fine grain microstructure also increases the abrasion resistance.
The effect of nickel additive decreases the size of TiC grains to submicron.
The coating with 15 wt. % Ni additions has an excellent grain abrasive resistance.

The role of mobile and immobile dislocations, grain boundaries, and pores is regarded.
Grain boundaries.
Then the vacancy flux near the grain boundary is 4aD/d2, and the number of vacancies, coming to a grain boundary per unit time, and calculated per unit volume, is 24aD/d 3 , which, on the other hand, may be written as (〈N 〉 − Ne)/τ = a/dτ.
From this follows that 1/Dτ = 24/d 2 for grain boundaries, which means that the mean free path of the excess vacancy inside a grain with respect to the grain boundaries is about 0.2d.
On the other hand this number is equal to the number of annihilating on dislocations vacancies per unit time, (〈N 〉 − Ne )/τ = −(a/2τ)ln(8.54lj2ndt).