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It was found that the propagation of cracks go along with the grain boundaries.
Note the very low grain growth, the average grain size is about 0.45-0.5µm.
In Fig.2c, the grain growth is not obvious, and the grain boundaries are clear and grain size strengthening function is distinct.
Some zirconia lie on the surface of the WC grains and was not embedded in the grains.
Meanwhile, some pores and fractured grains appeared, also.

A number of coarse borides aligned along the grain boundaries parallel to the extruded direction in the B-added alloy.
Grain Size (µm) FA FA-0.1B FA-0.3B FA-0.4B As shown in Fig. 2, sharp decreases in grain size after hot extrusion were observed for all specimens.
The coarse borides aligned along grain boundaries seem to hinder the growth of dynamically recrystallized grains during hot extrusion.
These results suggest that the borides strengthen grain boundaries.
Pang et al. [13] observed that the lath perovskite carbides inside grains and along grain boundaries increased the elongation in the Fe-40Al-0.6C alloy.

The microstructural analysis of damaged joints revealed that recrystallized grains form in the solder and crack progresses at their grain boundaries.
The thermal fatigue life was defined as the number of cycles in which the crack causes a 5% change from the initial resistance value.
From the result of the EBSD analysis, it was confirmed that the joint consists of a few grains at most although small tilt grain boundaries are observed within the grains.
Furthermore, from the GROD map, it was found that relatively large orientation differences are seen in the grains adjacent to recrystallized grains although there is little orientation difference within recrystallized grains.
The result means that stain energy is stored in the grains adjacent to recrystallized grains.

The EBSD technique easily and effectively provides information about individual grain size and orientation, grain boundary character and texture.
Deformation and strain can be visualized in EBSD maps in a number of different ways, e.g. [9-11] – EBSP Quality Maps, Boundary Distribution Maps, Local Misorientation Maps, Strain Contouring Maps.
Grains are slightly elongated parallel to the sample plain.
In the upper part, there is visible a scratch path, which demonstrates itself as through grain refinement and change in the grain orientation.
In IPF X maps we can observe gradual increase in green-coloured grains with deformation level.

Although a number of valuable contributions have already been published, the modeling and the development of accurate tools for strain localization prediction still remain an active research topic.
· is the total number of slip systems (equal to 12 for FCC single crystals)
The different microscopic mechanical fields are assumed to be homogeneous over each grain.
To go further with the derivations, an indicator function , for each grain of volume , is defined as . (20) The local fields can then be expressed in the form , (21) where (respectively ) is the volume average of the velocity gradient (respectively tangent modulus) for grain I, while is the number of grains that make up the studied polycrystalline aggregate.
All of the grains are assumed to be initially spherical with identical volume fraction.

The inner zone (I) is the early part of multiple nucleation and subsequent growth of the columnar microstructure having large number of interfaces, grain boundaries, micro-porosity and randomly oriented grains.
By increasing the total number of layers, the volume fraction of randomly oriented grains (near zone I of each layer) increases and as anticipated, was found to be less crystallographically textured when compared to a standard single-layered TBC.
Since the growth orientation of the new flux remains the same as the underlying grain, similar crystallographic texture occurs, but can vary depending on the total number of "shuttered" layers.
%Y2O3 k5hr Thermal conductivity, W/m-K Number of layers b) Fig. 9.
%Y2O3 was further reduced with increasing total number of layers (Fig. 9b).

The reason for this is the limited number of deformation systems that could be activated in magnesium crystals for plastic deformation at low temperatures [2, 3].
In cooperation with the project partners there are a number of alloys selected to be tested [Table 1].
The number of precipitations decreases significantly but those remaining grow slightly.
After heat treatment at 350 °C for 16 h the precipitates located at the grain boundaries and inside the grains are reduced.
The grain size is not influenced by the temperature.

Bulk NS materials are structurally characterized by a large volume fraction of grain boundaries (50% for 5 nm grains, 30% for 10 nm grains), which may significantly alter their physical, mechanical, and chemical properties in comparison with conventional coarse-grained (CG) materials.
Large grains may have enough space within the grains for significant numbers of dislocations to intersect/tangle with each other and, consequently, accumulate during deformation.
However, in NS grains, dislocations may no longer accumulate inside grains, and grain interiors are often dislocation free.
The importance of these two papers is attested by the large number of citations: 337+ and 503+, respectively.
Yonghao Zhao would like to acknowledge support by the Office of Naval Research (Grant number N00014-08-1-0405) with Dr.

When the bakelite content was lower, a great number of graphite particles were not packed by the insulated bakelite and rounded among ceramic grains.
Here the lower room temperature resistivity was covered up by the decrease of the number of ceramic grains joining in the resistance jump which were important to acquire a higher resistance over the curie point.
In some fixed content, more graphite particles spreaded around the ceramic grains symmetrically with higher graphite content, which caused the tunnel current to pass through ceramic grains with proper number of conducting accesses in room temperature.
When the molding pressure gradually becomes higher, the number of pore becomes fewer accordingly.
With the pressure increasing more, the extent of the continuity of bakelite among graphite particles improved and the number of conducting channels which were formed by graphite particles increased accordingly.

The dynamic recrystallization led to a small number of equiaxed grains.
These equiaxed grains are easy to form spheroidal grains during the soaking process in semisolid state.
No obvious elongated grains are found in the microstructure.
In the equations 1 and 2，, N and are area, the number and perimeter of solid grains, respectively.
The 1 value of R corresponds to perfect spheroidal grains.