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Results show that an increase in the number of FSP passes considerably enhances the dispersion of the SiC particles in the stir zone and also breaks down the SiC particles.
In this research, the effect of FSP pass number on dispersion level of SiC particles was investigated.
Table 1 shows the grain size variation at the different FSP conditions.
On the other hand, an increase in FSP pass number illuminates the agglomeration of the SiC particles.
Also the higher passes causes the SiC particles to break down which intensifies the pinning effect due to the presence of a higher number of dispersed particles.

After sufficient number of pulses (typically 15 to 20) of LEHCPEB treatment, this hardened zone can extend over hundreds of mm.
In turns, this reduces the number of nucleation sites available and the crater formation mechanism become less effective [8, 13].
These ultra fine grains are not the only reason for the generally observed surface hardening.
There is a fairly linear increase of hardness with the square root of the average grain size when the number of pulses increases.
This is illustrated by the EBSD map shown in Fig 4b where (i) the sub-grains are visible as white lines and (ii) the grains have blueish colors coresponding to near <111> orientations.

The most important characteristic of corundum is very high hardness (number 9 on Mohr scale).
It is referred in the Mohs scale as number 9, and thus represents the second hardest mineral after the diamond.
Sample number 1 is dust of white corundum, which is made by suction from un-magnetizing process e.g. removing free iron.
Sample number 2 is also white corundum, however its origin is from suction dust from manufacturing hall with drilling and separate machines.
Especially fine grain materials (grain size is in nano and micro meters) is a valuable indicator of quality.

Mechanisms of Ultrafine Grain Formation in Severe Plastic Deformation T.
The process of strain-induced grain formation can be subdivided in the following three stages irrespective of deformation temperature: i.e. an incubation period for new grain evolution in low strain; grain fragmentation by frequent development of MSBs in medium strain, and a full development of new grains in large strain.
The number of microband families running in various directions increases with further MDF, followed by a full formation of MSBs in large strain.
The authors proposed a model for strain-induced grain formation based on grain fragmentation by MSBs that is illustrated in Fig. 4 [8].
This subgrain-based model is assumed that new grain evolution takes place homogeneously in all grain interiors.

Computer Simulation of Grain Coarsening During Liquid Phase Sintering Z.
As the grains grow beyond the critical point pores start to decrease.
Our model assumes that for each pore there is a critical grain size required for filling.
As a consequence of grain growth, pores start to decrease because liquid flows into them.
A decrease in the number of pores (Fig. 3) and an increase in the average contour size with simulation time (Fig. 2) are evident.

Therefore, we proposed a new calculation model for austenite grain growth [3], which is based on the kinetic equation for grain growth via the Gibbs–Thomson effect.
In the phase-field method, each grain is distinguished by an ID number used to track every instance of grain growth and disappearance.
The grain growth rate of steel A is higher than that of steel B.
The grain boundary mobility increases as the temperature increases.
The theoretical grain growth estimated by the proposed model was consistent with experimental grain growth in the distribution of the prior austenite grain size in HAZ after submerged arc welding.

Changes in grain size, texture and misorientation distributions have been monitored during extensive normal grain growth in 3%Si steels.
The latter data were based on grain reconstruction with a minimum disorientation of 5º used to define a grain boundary.
The peak orientation density shows a slight decline during grain growth.
Fig. 6(b) presents limited misorientation measurements from recrystallised colonies which show that excessive numbers of low angle boundaries are already present at this stage.
Arita et al. [9] reported a similar profusion of low angle boundaries in a 0.5% Si steel when it had coarse grains prior to cold rolling and annealing but not when the prior structure was fine grained.

Keywords: brittle fracture, intergranular fracture, the strongest-link theory, grain boundary engineering, grain boundary character distribution (GBCD), grain boundary connectivity. 1.
However, thanks of the advent of the Orientation Imaging Microscopy (OIM) [10], we can very quickly determine by the computer-assisted OIM, the orientations of large numbers of individual grains, the size and shape of grains, and the character of individual grain boundaries.
Moreover we can obtain statistical information on the grain orientation distribution, the grain boundary character distribution (GBCD), grain boundary geometrical configuration and the grain boundary connectivity which define "the grain boundary microstructure", in addition to the average grain size and the grain size distribution widely used to discuss microstructural aspects of metallurgical phenomena in polycrystals.
So the toughening by grain boundary engineering will be more effective when polycrystalline materials have very fine grain size or even nanometer grain size. 4.
Achievement of Grain Boundary Engineering for Brittle Fracture Control Until recently, a rapidly increasing numbers of achievements have been made by the grain boundary engineering, since the early works on brittle fracture control in iron-6.5wt.

Abnormal grain growth is a discontinuous process, where a small portion of grains consuming the neighbor grains become selectively much larger than the latter.
It is true that the major driving force for abnormal grain growth is the reduction in grain boundary energy, but an additional driving force may be needed to overcome the circumstance that normal grain growth is being inhibited [5].
It is obvious in the early stages of grain growth that abnormal growth of the <111>//ND grains is distinguished as compared to the other oriented grains.
Existence of solute atoms to inhibit normal grain growth is a necessary condition for the occurrence of abnormal grain growth.
Also the concentration profile of sulfur atoms having an affinity for boundary segregation can be changed along the thickness direction without a great modification of the microstructures since the nanostructures contain a large number of interfacial areas.

Sodium hydroxide was used to modify distillers' grains (DG) assisted by microwave in order to comprehensive utilization of distillers' grains (DG).
China is a big liqueur producer, a large number of distillers’ grains, a co-product of a dry grind ethanol process, would come out.
Fig. 1 The SEM photographs of distillers' grains and modified distillers' grains Infrared Analysis.
The FT-IR spectrum of DG and MDG display a number of absorption peaks (Fig.2).
Fig. 2 FT-IR of distillers' grains and modified distillers' grains Effect of Sodium Hydroxide Concentration.