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This indicates that substantial amount of ZrO2 has transformed to m- ZrO2 as a result of ZrO2 grain growth.
Most mullite grains took a rodlike morphology with equiaxed ZrO2 distributed among them.
Many SiC nanoparticles (indicated by white arrows) were entrapped into mullite grains by breakaway from mullite grain boundaries during sintering (Fig.3(a)).
Therein, mullite grains also took a rod-like morphology, but the grain size was much smaller than the sample prepared by method A.
Acknowledgement This work was supported by the National Natural Science Fundation of China under grant number: No. 50402006 and No. 50672112.

There are studies[6,7] pointing out that M/A constituents with different morphology could strengthen the microstructure, but meanwhile they destroyed the continuity of base metal, and compared with blocky M/A, long-bar or angular M/A would dissever base metal and cause a certain number of lattice distortion, which deteriorated impact toughness.
By the statistics and analysis of grain size in simulated CGHAZ under different heat input, the results indicate that as heat input increases (from 6KJ/cm to 30KJ/cm), mean grain sizes in CGHAZ of 1# steel are respectively 39.8μm, 40.2μm, 40.1μm, 44.3μm, 44.8μm and 45.7μm, and mean size of original austenite grains has little increase; mean grain sizes in CGHAZ of 2# steel are respectively 30.6μm, 33.8μm, 44.7μm, 45.5μm, 56μm and 69.8μm, and mean size of original austenite grains has obvious increase, especially when heat input is higher than 20KJ/cm, it is found by the further combination with microstructure characteristics that mean grain size rises obviously after 30KJ/cm which is more than twice the size of 6KJ/cm.
What’s more, austenite grains are variable in size and there are small grains among big ones, which indicate the increase of heat input worsens both microstructure uniformity and toughness [8].
High alloy content inhibits the growth of austenite grains.
Microstructure of 1# steel is mainly composed of granular bainite, bainite ferrite and M/A, and the grains are fine.

The solid ice and snow constitutive model was established, which the deformation mechanism of snow microstructure and macroscopic continuous behavior were linked together, considering the damage of solid ice and snow depends on the mechanical properties of the snow volume elements of the grain bonds between grains, and using the microstructure factor scale the stress state of microstructure in the continuous stress.
The constitutive model The microscopic model of ice and snow The mechanical behavior depends on the snow volume elements of the grain bonds in grains was taken into account when established the model.
Namely, considering the macroscopic behavior was controlled by the movement of skeleton of ice grains.
Fig.1 Microstructure definitions Fig.2.Continuous description of the normal direction of contact Definition of representative volume element A volume element around a point was considered when analyzed the model, in which the number of grain bonds is large enough so that this volume can be described as a continuous material.
Definition (a) and modelling (b) of an ice bond between two grains in contact Microscopic contact stress analysis The contact form of ice grains as shown in Fig.3, when analyzed the mechanical properties of ice grain bonds, taken the gravity effects into account, a stress state is generated at each point of the neck.

Effect of the Grain Size of Sand on Expansive Soil Yahya K.
Grain size of the Bentonite/Sand soil mixture.
The grain size distribution was conducted according to the ASTM (D421- 85-1972 and D422- 63-1972).
The maximum reduction in swelling percentages was obtained from D40 soil; on the other hand, the fine grain sand (sieve No. 200) gave inverse results with the highest swelling percentage in compared with other grain size of sand used (see Fig. 5).
The soil D200 had the lowest surface area among all the soils because of the minimum numbers of bentonite particles being replaced by sand particles.

(2) The data document obtained, namely matrix, is in turn divided into several submatrix, in which the number of rows and columns in submatrix is k.
The number of non-zero submatrix is written as Nk, in which k is taken 1, 2, 4, 8, … , 2j , namely taking the size of 1, 2, …., 2j pixel as side length to divide the submatrix, thus obtaining the box numbers N1, N2, N4, … , Nk.
The smaller Fd expresses that microstructural morphology is simple and regular, and the roundness of grain is better.
During formation and growth of primary phase, because of affecting by preparing condition and external physical field (for example pouring temperature, isothermal holding, ultrasonic or mechanical disturbance, addition of modifier and so on), there will be change on the morphology, size and structure for primary phase grain, at the same time, there is other change, included growth and migration of the grain, even fuse and separation of the grain to make morphology of the grain change.
The Fd of its morphology also correspondingly changes during growth and evolution of grain, and the Fd also gradually changes with the continuous growth of primary phase grain.

SEM of fractured cross sectional portion showed that smaller grains were formed in case of microwave sintering.
Average grain size was calculated using linear intercept method and calculated value of average grain size and porosity of the samples are given in table1.
From this table it is observed that the grain size increases with increase in sintering temperature for both cases.
That can be attributed to low grain size in microwave sintered samples because smaller the grain size larger number of grain boundaries which resist the movement of electrons hence increase the resistivity9.
SEM of fractured cross sectional portion showed that finer grains were formed in case of microwave sintering.

Sample Name Total number of layers Intermediate heattreatment during rollbonding process Further deformation after last rollbonding Ave.
In contrast, there is nearly no difference between the as-deformed and annealed states for the grain diameter distribution for the 92% deformed sample, fig. 5b. 0 0.05 0.1 0.15 0.2 0.25 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 More Grain Diameter (micron) Number Fraction 0% 5% 10% 15% 20% 25% 30% 35% 3 7 11 15 19 23 27 31 35 39 43 47 51 55 59 Misorientation (degree) Frequency 0% 5% 10% 15% 20% 25% 30% 35% 3 7 11 15 19 23 27 31 35 39 43 47 51 55 59 Misorientation (degree) Frequency 0 0.05 0.1 0.15 0.2 0.25 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 More Grain Diameter (micron) Number FractionDiscussion For the alloyed Cu C19210, the R component, {124}<211> dominates the recrystallization texture instead of the Cube component which was obtained for the monolithic pure Cu sample.
Instead, the close sub-micron spacing of the Nb layers may impede both nucleation of new grains and the growth of new grains if they are formed, thereby allowing the other grains in the deformed state to recover and grow instead.
The increase in the pinning effect of the Nb layers on the growth of grains in the Cu layers is also evident in the grain diameter distribution.
The EBSD scans were accomplished using facilities provided by the Mesoscale Interface Mapping Project under the MRSEC program of the NSF, grant number DMR-0520425.

At 500 °C, complete recrystallization occurred with minimal grain growth, while 550 °C caused grain coarsening, partial grain boundary melting, and morphological changes of the LPSO phase from lamellar to spherical and rod-like structures.
After hot rolling with an equivalent strain rate of 17 s-1 the average grain size was estimated as 28 µm ± 13 µm, as the microstructure consists of a mixture of larger grains and big grains which are elongated in rolling direction as shown in Fig. 1a.
The LPSO phase mainly precipitated at the grain boundaries, only a few spherical structures can be found within the grains.
The as-rolled microstructures featured α-Mg grains and LPSO phases at grain boundaries and within grains.
Funding This research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project number 497456843.

The wear of abrasive grain is mainly physical such as abrasion wear, grain fracture and bond fracture since CBN is more chemically stable in higher temperatures [2].
Meanwhile, the number of effective grains is increased so that the wheel wear is slowed down.
Grinding wheel wear also leads to the changes of the number of active grains which has great effects on the ground surface.
The feed rate per revolution s can be reduced by increasing the workpiece speed, so the number of steps increases.
The sources of AE in grinding process are mainly the bond and grain fracture, grain cracks and friction between abrasive grain and workpiece, all of them directly connected to wheel wear [7].

The higher pressure resulted in an ultra fine grained structure with a smaller grain size and higher density of defects compared to the sample prepared with the lower pressure.
One can see that it contains a high number of dislocations.
However, the sample A exhibits smaller grain size compared to the sample B.
Thus, grain growth takes place at temperatures lower by about 100 ˚C in the sample B with the smaller initial grain size of 105 nm compared to the sample A with the initial grain size of 150 nm.
Figure 5 Mean grain/domain size as a function of annealing temperature.