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Twinned WC grains are sometimes observed in WC powder and sintered WC-Co alloys.
Eta grains were carburized at 700-1450℃ for 1 min to 9 h.
Twinned WC grains formed during the carburization.
A number of investigations have been made on the formation of the twins in WC[2-6].
The types of twinned WC crystals or the carbon position in each sides can be determined by the number of stacking faults in the growing crystal.

Whether this occurs depends on the misorientation between the grains and the resolved shear stresses in the affected grain.
In general, one might expect multiple dislocation pile-ups along the GB area with varying number of dislocations in each of them, as considered in an earlier publication.
To take into account the effect of the entire pile-up, the following integral has to be performed: F12PU=Nl-l0δα1l-12δα1l-δα12l2F12δα1dδα1 (9) N is the number of dislocations in the pile-up (positive and negative).
The grain diameter was taken equal to 10 mm and the number of dislocations in the pile-up was taken equal to 100, the elastic constants used are the ones for copper and the critical resolved shear stress was put equal to 20 MPa.
Nonetheless, if the Schmidt factor of the second grain is not too low, a much lower number of dislocations could produce the critical punch-out stress locally for certain combinations of misorientation and grain boundary normal.

Dynamic grain growth, and its related mechanisms, has been the subject of a number of studies [7-13].
The present paper concentrates on the dynamic grain growth behaviour of the SP AA5083 alloy, and particularly on the effect of rapid pre-strain on the grain size, for a given strain, relative to the grain size under constant strain rate conditions.
For each sample, over two thousand grains were analysed.
Shows (a) average grain size, and linear intercept grain sizes in (b) RD (c), TD and (d) ND as a function of time.
In the first stage there would be significant grain elongation with some grain growth, while in the second stage the grains would continue to elongate but would show significant grain growth.

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.

Stereology of Grains in Nano-crystals T.
Grain size homogeneity can be measured and the variation in the grain's elongation.
Grain volume If the investigation of nano-materials is focused on grains rather than grain boundaries, the most natural size parameter is grain volume, V.
The density of grains can be subsequently obtained by dividing the number of counted grains, N, by the studied volume of specimen, Vo: NV = N/Vo
Principles of Saltykov reconstruction Grain size homogeneity, grain shape and grain arrangement Population of grains in polycrystals may differ not only in the mean value of their volume, V , but also in terms of the width of the grain volume distribution function.

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.

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].

However, as for the fine-grained cassiterite, flotation and joint processing techniques are generally selected to improve the low recovery from gravity separation.
According to the studies of a number of tin ore bodies, tin can be classified into three major groups [2]: Cassiterite contained in pegmatite veins contain significant quantities of (Nb,Ta)2O5 with traces of wolframite and manganese.
The commonly used beneficiation method for coarse-grained cassiterite is gravity separation and for fine-grained is flotation.
Carrier Flotation Carrier flotation is that floatable coarse mineral particles are added into the pulp as a carrier, fine-grained particles adhere to the carriers or fine-grained particles themselves flocculate together, then the coarse particles are collected out.
Conclusions Though various flotation regents can be used for cassiterite separation, a number of difficult problems still cannot be avoided due to bad selectivity, high cost of the reagents, low index and serious environment pollution.

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.

Critical nanometer grain sizes and deformation mechanisms The nanometer area a grain size approaches to the thickness of grain-boundary layers.
The polycrystalline grains are numbered.
In grains 3 and 4, the dislocation sources are triple grain junctions, whereas in grain 2, these are steps in the boundary between grains 1 and 2.
In Table the critical intervals of grain sizes from nano to mezo grains.
The stages with even numbers (II, IV, VI) have a constant value Θ, the stages with odd numbers (III, V) have the value of Θ decreasing with deformation.