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In the mechanical and the evolutionary process, powder is repeatedly mixed, collision, cold welding, tearing, forming a homogeneous nano-crystal line supersaturated solid phase and amorphous phase [3], and as a result of continuous extrusion and deformation, so that the particles produced a lot of dislocation and defects, grain refinement, while a large number of lattice distortion and nanometer grain boundary formation activity increases, which is favorable for subsequent sintering.
Mechanical alloying preparation ultrafine W-Cu composite powder has the advantages of high yield, simple process equipment, small powder grain size etc.
W-Cu composite powder obtained has a uniform fine grain structure.
The spherical powder can be pressed and sintered density, fine grained W-Cu composite material.
This method can be prepared from the high sintering activity, has a fine grain structure of the W-Cu composite powder.

«Quenching (in water at 1,133 К) + ECAP (route Вс, 673 К, the number of passes n=8) + annealing (873 К)» resulted in 16 times higher toughness of the Fe360 steel at 213 K testing temperature as compared to the initial state.
Measurement of average grain size was performed by the method of secant.
Quenching in water at 1,153 K and n=2 ECAP runs along the C route at T=673 K resulted in a fine-grained structure with an average grain size of 4.5 µm (Fig.1b).
The consequent annealing at 873 K led to a slight grain growth to 5.6 µm (Fig.1c).
Annealing at 673 K provided both a fine-grain structure formed in annealing, ECAP and higher toughness.

SiAlON is a solid solution based on silicon nitride where some silicon is replaced by aluminium and some nitrogen by oxygen and it occurs in two phases; α-SiAlON and β-SiAlON. α-SiAlON appears in the microstructure of the sintered material as equiaxed grains, is very brittle but with a high hardness (2000 HV1), and low fracture toughness (KIC = 4-5 MPam1/2). β-SiAlON appears as elongated needle-like grains, is relatively tough (KIC=7-8 MPam1/2), but reaches only a hardness of about 1600 HV1. [2]The present commercially used cutting tools consist of β-SiAlON, this type has a quite high fracture toughness and thermal conductivity but does not have sufficient hardness for some machining purposes.
To achieve substantial change in microstructure from surface to inner core and sufficient toughness in a SiAlON-structure there are two possibilities: first to change the outer region in to α´-SiAlON and to keep a β-or (α + β) core-or second to change the α-structure in a way that elongated grains can cause the desired toughness property. [4].
Both methods are feasible with the design of the SiAlON material, this includes the careful control of the complex chemistry (e.g. amount of the glassy phase at the grain boundaries) and the careful control of the sintering process.
The rim region was rich in α-SiAlON in comparison to the core region, which possessed a higher number of elongated grains.

For over a number of years, many researchers have attempted to decrease the sintering temperature of BaTiO3 based ceramics through the use of various sintering aids such as B2O3, Li2O, etc. [3].
There was no change in the grain size, nor is there any evidence of abnormal grain growth in the annealed sample.
The grain size of the sample was found to increase with increasing the sintering temperature.
It may be due to the effect of grain size that as suggested from Jin et al. [5-6] that the dielectric constant depends strongly on grain size.

In this case, the grain size of AZ91 billets was about 55μm and that of AZ31 billets was 50μm.
Moreover that had primary α crystals is average grain size of 55μm in AZ91 and that of 50μm in AZ31 on fig. 4, where primary α crystals are the bright area and eutectic structures are the gray area.
As a result, fig. 7 proved that microstructure of castings produced constant for the number of shots.
The average grain size of billets is 50 to 55μm. 4.

HPO42- off H+ to obtain PO43 calcined from 800oC to 900oC, which alters the atomic number of the cation and shifts the absorption of the anionic groups slightly.
Its front line, the number of peaks are the same as CaZr4(PO4)6 indicating that their space group is consistent.
It can be observed that microstructure is quite uniform, fewer porosity, irregular shape of the grain, and arranged in a dense.
Crystal is more clear, you can clearly see the combination of more closely between the grains, sintering obvious.
The grain boundary is not obvious due to the high temperature.

The bainite ferrite with obvious interface increase gradually in the microstructure with the applied stress (Fig. 2 (b), (c), (d)), the uniformity of microstructure is incresed gradually, and the average grain size decreased gradually.
From the figures, corrosion products is white round granules (melting bead), product surface is not only the number is large, but the size is big, the rusty layer is very loose, which shows the honeycomb.
In the electrochemical corrosion, M-A Island is the cathode phase , ferrite matrix is the anode phase, and a large number of M-A islands in microstructure increase micro-battery cathode area significantly , which accelerated the corrosion of steel.
Thus, the number of micro-cell in steel reduced greatly, so the corrosion resistance of steel is improved greatly.
In addition, the presence of M-A islands in granular bainite increased the area of the grain boundary, which is also an important reason that granular bainite steel displays poor corrosion resistance.

In the temperature range 700 to 1000 °C, the test steel with ferritic-pearlitic structure with a small grain growth.
The heat treatment above 1000 °C increases the amount of ferrite in the structure, and a strong growth of grain size.
Answer steel industry to these needs from a number of international projects involving a number of companies including ULSAB-AVC (called Ultra Light Steel Auto Body - Advanced Vehicle Concept) or the TRAILTECH Arcelor Mittal, whose purpose is the development and production of components with high strength steel, which guarantees good formability.
A further increase in temperature above 1000 °C, resulting in a strong proliferation of grain (Figure 1).
Additionally, in this temperature range, grain growth occurs which results in a rapid decrease in the impact strength values of several J/cm2 (Figure 4).

The effect of the Al diffusion coating on the fatigue life depends on number of factors [3-5].
Polished sections of the material reveal coarse grains with dendrites, carbides and shrinkage pores being rarely up to 0.4 mm in diameter.
Rugged grain boundaries due to the complex dendritic structure are apparent.
The average grain size, found using the linear intercept method, was 2.3 mm.
Hysteresis loops for selected numbers of cycles were recorded in disk memory.

For polycrystalline materials, the degree of deformation is different from one grain to another according to their own orientation.
And the grain boundaries with an enrichment of low-melting materials can be melted easier and act always as the initial nucleation site of craters, as shown in Fig. 1(c).
Wave-like contrast was also found beneath the hear-affect zone beside grain boundaries and it can penetrate small-angle boundary, shown in Fig.2 (d) and (e).
Fig. 4 shows the changes of coefficient of friction depending on the number of fretting cycles.
Number of fretting cycles, Fn=100N, N=5000cycles. 0 2 4 6 8 10 12 D2-Cr D2-TiN D2-3 D2-1 D2-0 Fretting wear volume(105 µm 3) specimens Fig. 5 Fretting wear volume of specimens