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Due to the large number of participated abrasive grains, random shape, size and location, and higher grinding speed, it’s extremely difficult to study the formation mechanism and material removal mechanism of grinding surface.
Based on the relative motion trajectory of the abrasive grain and workpiece, the single abrasive grain grinding experiment can be divided to pendulum and swipe.
Single Abrasive Grain Grinding Experiment Single abrasive grain grinding experiment in the type of pendulum.
Adopting single abrasive grain grinding experiment, E.
Exchanging the position of abrasive grain and the workpiece, B.

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.

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.

TEM image of the two kinds of precipitates in as-rolled tested steel A great number of precipitates, see Fig.1, which appear to be nearly rectangular or spherical, in tested as-rolled microalloyed steel were revealed under TEM.
As seen from the Fig.4(a), the finer austenite grains distribute inhomogeneously as new austenite grains contact with each other and the grain boundary is bent.
Under the temperature of 1100℃, the average grain size of austenite is less than 50μm; from 1100℃ to 1270℃, the grain size grows up gradually; at the temperature above 1270℃, the grain size increases rapidly.
However, under the same condition, effect of holding time on the grain size is less obvious than heating temperatures on the grain size of austenite.
Consequently, the grain size increases tremendously.

At present work it is based on the Fe-40Ni-Ti alloy to simulate the grain boundary migrated process of HAZ in rapid heating process, observe the action between the boundary and TiN, simulate the grain growth behavior of austenite grains.
The grain size in different heat zone was measured by using the line transect method [5], and the grain number of statistics is at least 300. 18mm 4mm F10mm a b c Fig.1 Thermal simulation test of the sample (a) welding line, (b) HAZ, (c) parent metal Results and Discussions Curve characteristic of rapid heated process The rapid heating up curve at thermal simulation machine was shown in Fig.2.
The grain growth is not obvious at HAZ and parent metal.
If the grain boundary energy anisotropy is significant, in order to reduce the process barrier, the grain boundary curvature changes small during the bypassing process, and if the grain boundary energy basic isotropic, in order to reduce the total area increase, the grain boundary curvature near the precipitates becomes very large.
(2) TiN particles have obvious effect on the grain boundary migration, the grain boundary energy change a little with the grain boundary orientation change.

With reference to the characteristics of polycrystalline materials, according to contemporary terminology UFG materials may be defined as polycrystals having very small grains with average grain sizes less than ~1 mm [1].
Mechanical properties of steel AISI 321 and structure parameters after HTMP with different numbers of passes n and different rolling reduction, e.
The volume density of the precipitates increases and their size decreases up to 0,1 mm as the number of passes increases.
Langdon, Twenty-five years of ultrafine-grained materials: Achieving Exceptional properties through grain refinement.
Micro-Mechanical Responses of Ultrafine-Grained Materials Processed through High-Pressure Torsion.

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.

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.

The permeability of coarse-grained soil is influenced by many factors.
In practical projects, the number of engineering accidents caused by seepage at home and abroad is also very large.
There are many factors that can decide the seepage properties of coarse-grained soil.
Coarse-grained soil that got in a hydropower station dam is artificially burdened into 12 samples to study on the permeability coefficient of coarse-grained soil.
The particle size of soil sample is 0.0~60mm and the sample is numbered 1-1~4-4.

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.