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Ultrafine grained materials prepared by methods of severe plastic deformation appear to show good ductility for their high strength.
Analysis of Ductility of Ultrafine Grained Materials Ductility of Al Alloys Deformed by ECAP.
There are some suggestions that grain boundary processes, such as grain boundary diffusion or grain boundary sliding, may modify the work hardening behaviour, the strain rate sensitivity, and also the ductility [31,32].
While it seems unlikely that significant grain boundary diffusion/sliding will occur in Al for the relatively large grains considered in the present work (of the order of 0.3 µm), such effects have nevertheless been suggested in a recent publication [32] for similar alloys, grain sizes and deformation conditions to the present study.
This recovery occurs because of the inhomogeneous microstructure produced by the severe plastic deformation - cell or grain interiors/cell or grain boundaries - and the associated internal stress distribution.

It is obvious that a large number of reinforcement particles agglomerate in the matrix, indicating that the higher content of reinforcement are added, the more regions of agglomeration occurs.
Finally, a large number of grain boundaries were generated as the addition of AlN particles can increase the interface area in composite.
Grain refining technology of magnesium alloys [J].
Grain refinement of AlNp/AZ91D magnesium metal-matrix composites [J].
Fu.Grain refinement by AlN particles in Mg-Al based alloys [J].

In order to quantify the elastic anisotropy of the mantle peridotites, texture measurements were performed on a number of samples from the lherzolite unit of the Finero complex and the elastic moduli were calculated from the mineral textures.
Since the samples are coarse grained, the neutron diffraction method was applied to ensure sufficient grain statistics in the texture experiment.
To overcome the statistical limitation caused by a large grain size, the texture scan was performed on a very large sample surface.
All samples are coarse-grained with olivine grain sizes of up to a few millimeters, samples IV1 and KU1 show the largest grain sizes.
Numbers close to these principal sample directions indicate particular velocities in the pole plot; S and L indicate foliation and lineation, respectively.

PWHT was observed to result in grain coarsening, sub-grain structure formation and decrease of the dislocation density.
Recent studies indicate that FCAW has a number of advantages over the common welding techniques available that use solid wires, such as manual metal arc welding and gas metal arc welding [3].
TEM images of dislocations (Fig. 4.) showed dislocation pile-ups at the grain boundary and some sub-grains after PWHT.
In the early stages of the sub-grain formation, an ordered dislocation alignment occurs and forms new boundaries inside the grains.
The drastic increase in the impact toughness after PWHT is attributed to the effect of softening, grain growth, precipitation and formation of sub-grains. 2.

Although the number of studies are limited compared to Ti oxide, some studies have demonstrated the positive effect of Zr oxide in improving the performance of steel [7-10].
The average prior austenite grain size was about more than 200 μm and the grain boundaries (GBs) were outlined by ferrite (GBF).
Most of the grain boundary ferrite was polygonal (PF), while some grew along the GBs.
In the present steel, a number of fine oxide inclusions could be obtained as a result of Ti-Zr deoxidation.
Thus, the austenite grains in the HAZ did not grow extensively.

The coarse grained α-Al2O3 layer shows similar adhesion compared to the fine grained α- Al2O3 in scratch test.
The failure mode of the coating with coarse grained α-Al2O3 layer in the repeated impact test is primarily impact wear.
Coating A has a fine grained α-Al2O3 layer with the grain size about 1 µm and C is of the same phase but the grain size is about 4 µm, whilst the alumina layer of coating K is κ-Al2O3.
After a given number of loading cycles, the sample was cleaned to remove the debris before the observation of the impact dents through an optical microscope.
This brings about longer damage cycles than that of the fine grain one.

It was found that after annealing the sigma phase particles were precipitated at grain boundaries and within austenite grains.
A number of specialty austenitic stainless steels have been developed to meet exceptional conditions of application.
Sigma phase can be formed at grain boundaries as well as within grains and can cause an increase in hardness.
Precipitates observed at grain boundaries and within the grains demonstrated different shape and size (Fig. 2b).
Precipitates, which existed within the austenite grain, are fine-grained and have an oval shape.

The preservation of base metal’s microstructure after welding results from the precipitate morphology, such as high grain boundary coverage by precipitates and low amount of MX being nucleation sites of ferrite grains during the a-g phase transformation.
Also, a, b, c, and d respectively represent the numbers of Fe, Cr, C, and B atoms in the compounds.
Moreover, because the TA steel contains a low amount of MX precipitates which act as nucleation sites for ferrite grains during the a-g phase transformation [17], the grain size might be coarser in HAZ.
Sahara, Suppression of grain refinement in heat-　affected zone of 9Cr-3W-3Co-VNb steels, Mater.
Smith, Grains, phases, and interfaces–an interpretation of microstructure, Trans.

The rate of drying is affected by a number of factors such as initial moisture content, drying air temperature, relative humidity, and airflow rate.
However, the geometry of a rice grain is closer to an ellipsoid geometry.
Besides, rice grain was considered to remain isothermal during drying.
It was also assumed that rice grains did not shrink during drying.
The dimensions of a grain and the corresponding ellipsoidal geometry were determined by Hacıhafızoğlu et al. [7, 8] by averaging measurements for 100 rough rice grains, which are given in Table 1.

However, the mechanical stability of austenite could not be simply influenced by the average grain size, as the austenite grain size is inhomogeneously distributed.In the present study, the influences of the average grain size and maximum grain size of austenite on themechanical stability were analyzed.
The microstructure of 800-5 steel (Fig. 1b)shows a large number of sub-micron scale α-ferrite with granular and lamellar morphologies embedded in the prior austenite matrix.
The grain size of austenite grew with increasing annealing temperature to 900 ℃, and the equiaxed grain of α-ferrite existed in the austenite bands (Fig. 1d).
Compared with 800-30 steel, 900-5 steel had a higher proportion of large-sized austenite grains, and the grains larger than 5μm can be observed.
B and vγ are the geometry coefficient of austenite grain (475 μm·K) and the average volume of austenite grain, respectively.