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The grain boundary fracture toughness (KICgb) was estimated from a percentage of the intergranular fracture as a grain boundary property for each specimen.
The number of sliding pass is one.
After the sliding test, the surface of the sample was observed by scanning electron microscopy (SEM), and the number of grain boundary microcracks as mechanical damage was countered on 50 SEM images of each sample.
The relationship of the amount of silicon debris and the number of microcracks showed qualitatively inverse proportion, namely, the amount of silicon debris increased with decreasing the number of microcracks.
Arrows indicate grain boundary microcracks.

In the pole figures, the numbers are the grain 1 2 3 1 1 1 2 2 2 2 3 3 3 3 1 numbers in the orientation map, the lines in d are the orientation distribution ranges of the deformed grains taken from b, and the solid circles show the orientation of the nucleus.
The nucleus/grain has a <111> pole in common with grain 6.
Even more it has a misorientation of 39.8º/[-0.61 0.51 -0.61] to a few pixels near grain boundary in grain 6.
If the grain boundaries after annealing are overlapped onto the grain boundaries before annealing (Fig. 5), it can be observed that the nucleus mainly has grown into grain 4, which has a misorientation of 20.3º/[-0.43 0.88 0.18] to the new grain.
In the pole figures, the numbers are the grain numbers in the orientation map, the lines in d are the orientation distribution ranges of the deformed grains taken from b, and the solid circles show the orientation of the nucleus.

Measurements were made on a statistically representative number of microstructural elements.
The deformed regions tend to have a large number of lowangle grain boundaries and there is a greater fraction of these at the higher strain rate (Fig. 3). 15 20 25 30 35 0 0.2 0.4 0.6 0.8 1 Strain Mean grain size, µm Non-deformed part Deformed part Fig. 1 left: EBSD maps for the deformed (strain: 0.9) and non-deformed regions of tensile specimen of the Al-4wt.
~3.33 hrs ~1.28 hrs 10-4 s-1 10-3 s-1 Non-deformed regions Deformed regions 225 µm 225 µm ND RD, σ In a number of works [6-10] dynamic grain growth was well-described using an exponential expression )exp(0 ελ⋅= DD , where 0D is the initial grain size and ε is the strain.
A number of works [11-15] have shown a similar effect after plastic strain, however, without particular relation to dynamic grain growth.
There is no doubt that behaviour of the second phase particles during deformation of an abnormally large grain structure cannot be absolutely the same as that in the presence of a large number of high-angle grain boundaries.

Introduction Nanocrystalline materials consisting of nanometer-sized crystallites contain a large number of interfaces, i.e. grain boundaries and triple juctions, which a large volume fraction of the atoms are associated with [1].
Such nanocrystalline electrodeposits are in non-equilibrium (metastable) states, i.e. high energy states due to a large number of interfaces [2, 3].
The temperatures Journal Title and Volume Number (to be inserted by the publisher) 3 corresponding to the exothermal processes are higher in Fe-Ni alloys than that in pure Ni, but the positions of the peak maxima are different depending upon the alloy compositions.
The fact that the <111>//ND grains are much coarser than the <100>//ND grains in the fully annealed specimen is attributed to the abnormal grain growth of the former in the early stages of grain growth.
Journal Title and Volume Number (to be inserted by the publisher) 5 (a) (b) (c) Fig. 5 OIM maps and the corresponding ND inverse pole figures in electroformed Fe-36%Ni alloy after annealing at 390°C for various holding times: (a) 0 min; (b) 5 min; (c) 30 min.

The minimum grain size (85µm) was achieved at 0.4wt.% Zr.
This unique property has led to the development of a number of commercially important zirconium-containing magnesium alloys.
The mean linear intercept technique was used to quantify the grain size with at least 500 grains examined.
However, potent nucleating particles can be effective for grain refinement only if they have sufficiently high particle number density in the melt.
When Zr content is larger than 0.443%, the un-dissolved Zr particles will experience rapid coarsening under intensive melt shearing, resulting in a rapid decrease in particle number density, which in turn gives rise to an increased grain size (Fig. 4).

As the breakdown voltage of a varistor is the sum of the breakdown voltages of all the non-linear (varistor) grain boundaries between the electrodes, it depends on the number of grain boundaries per unit thickness of varistor ceramic, which is inversely proportional to the ZnO grain size.
The anisotropic and exaggerated growth of grains with IBs (nuclei) is caused by a nucleation mechanism for special boundaries.[17] For a smaller number of nuclei a coarsegrained microstructure develops, as the nuclei can grow to a larger size before they collide with each other.
However, if the number of nuclei is large they collide with each other when they are still small, which results in a fine-grained microstructure.
Sufficient amount of Bi2O3-liquid phase at the grain boundaries and inversion boundaries in the ZnO grains promote grain growth.
Amount of added Bi2O3 defines the amount of liquid phase at sintering temperature while the amount of added Sb2O3 affects nucleation of IBs in the ZnO grains at the early stage of sintering and hence number of grains infected by IBs which can grow exaggeratedly.

The specimens were observed under an optical microscope and a number of pictures were got in order to study the grain size.
The number of grain size in HAZ of the 3 group is counted.
The average statistics of grain size number are shown in Table 4.
From Table 4, it can be observed that grain size numbers of all the areas tested were larger than 6.
Table 4 Grain size number Zones Group HAZ-1 HAZ-2 HAZ-3 HAZ-4 A 6.54 6.96 7.07 7.09 B 6.45 7.34 6.98 7.08 C 6.37 7.05 6.44 7.06 Comparing the grain size in A, B, C, the 3 group, it can be obtained that as the heat input increases the influence on grain size is more obvious.

The main shafts, after final heat treatment, should have a grain size of number 5 or finer according to ASTM E112.
Table 4 Technological parameters of WHF method number of laps 1 2 3 4 5 6 7 8 height before drawing out 2860 3000 2420 2630 2180 2330 1970 2070 height after drawing out 2290 2400 1940 2100 1740 1860 1580 1660 reduction 570 600 480 530 440 470 390 410 tool width ratio 0.524 0.500 0.620 0.570 0.688 0.644 0.761 0.725 Heat treatment after forging, as shown in fig.2, includes three times normalizing and tempering in order to gaining fine grains.
There is a serious mixed grain phenomenon in the first technology (without Nb), which grain size is grade 2-5, as shown in fig.3, While the average grain size of the second technology (including Nb) is grade 8.2(fig.4).
The final average grain size is grade 7, as shown in fig. 5.
(2) The refined steel with VCD treatment results in grains growing up easily, but the correct heat treatment can fine grains effectively.

Each point is called "lattice point" and is assigned a random number Si between 1 and Q, where Q is the total number of grain orientations at initial state.
Here the number of Q is chosen as two due to the bicrystals.
It is observed that the upper grain A obviously has less deformation than the lower grain B.
These observations show the grain migration from the lower grain B into the upper grain B after 2 hours at 450°C as shown in Fig. 2(b) and (c).
In section III, however, grain A moved toward grain B, and the mobility was small that the grain boundary hardly move after annealing 3 hours at 450°C in Fig.2.

Results and Discussion The percentage results for certain grain orientations and grain size distribution for all grains in the matrix and particularly for the Goss grains are been shown.
Grains having diameter lower than 21μm will be called small grains, grains with diameter between 21 and 42 μm will be called medium grains and finally, grains having diameter higher than 42 μm will be named as large grains.
For the samples annealed without field, the number fraction of small grains decreased as the annealing time increased being 48.4% on sample O3 and 34.6% on sample O30.
For the magnetically annealed samples the number fraction of small Goss-grains increased with increasing in annealing time, principally from 3 and 15 minutes.
Comparing the development of the Goss-oriented grains in the samples annealed with and without field, after 3 minutes of magnetic annealing, the small Goss grains are in less number and their percentage increases with time becoming equivalent after 30 minutes.