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The results show that Ni particles uniformly coat on the surface of powders and then transform into NiTe2 during the sintering process, after that NiTe2 mainly concentrated at the grain boundaries of bulk.
The grains changed from ellipse to circle with Ni content increasing, which implies that the Ni-coating may influence the grain shape during the hot-pressing process.
It hints that Ni is concentrated on the grain boundary and be formed into a “net structure” during the hot pressing process which is beneficial to electronic transport along this electron channel.
(3) where κel is the electronic thermal conductivity, L(L=2.45×10-8 V2/K2) is the Lorentz number, T is the temperature, and ρ is the resistivity.
The phase of NiTe2 primarily concentrating at the grain boundaries provides extra carriers and electron channels to increase the electrical conductivity but to damage the Seebeck coefficient.

The cellular initiation site (grain boundaries, inclusions) and regimes of lamellar divergency-cum-slowing growth rate were explicitly accounted for.
The apparent activation energies Q were similar for grain-boundary and inclusion-nucleated discontinuous precipitation, indicating that their nucleation site does not alter their overall kinetics.
The DP was further subdivided into amounts attributable to grain boundary (DP-GB) and carbide inclusion (DP-Inc) initiation sites.
Gray boxes indicate insufficient data for an Avrami fit (e,f) or for error evaluation because the number of data points was equal to the number of fitted parameters, two (h).

The influence of the spindle speed, feed rate, workpiece geometry and planar anisotropy of the blank on the strain distribution of formed part is studied by method of grain size measurement.
The grain sizes were calculated by linear intercept segment method using straight test lines on a polish section of the specimen (Fig. 3).
Straight test lines placed over a non-deformed (a) and deformed (b) grain structure In the next step of strains analysis the influence of spindle speed, feed rate, workpiece geometry and rolling direction of the sheet on major true strain were evaluated.
The Taguchi L27(313) orthogonal array, which has 27 rows corresponding to the number of tests (26 degrees of freedom) with 13 columns at three levels, was used in this study [13].
Steels - Micrographic determination of the apparent grain size. 2003

With increased forge pressure, recrystallized grains remaining in the weld were minimized.
For polycrystalline materials, if sufficient frictional heat is generated during LFW, the availability of a large number of active major slip systems readily allows thermal softening or plasticity to occur.
At the weld interface, the high intensity of shear deformation combined with sufficient thermal conditions resulted in the formation of recrystallized grains which were difficult to differentiate or measure optically (Figure 4b-c).
Using backscattered imaging, the microstructure in the weld region was observed to consist of fine recrystallized grains, roughly 5 mm in size, as illustrated in Figure 5.
In the region surrounding the weld interface, recrystallization occurred and fine grains, roughly 5 mm in size, were observed.

Tab.1 Chemical composition of test steel EH36 (wt%) C Mn P S Si Ti Al Nb V Ceq Fe 0.15 1.45 0.008 0.003 0.35 0.01 0.036 0.03 0.08 0.399 Bal 2.2 Heat treatment process Tab.2 Hardening and tempering heat treatment process system and sample serial number Serial number Technological conditions technological system Serial number technological system A TMCP After rolls over the sample E 910℃/30min+500℃/30min B hardening 950℃/30min F 910℃/30min+550℃/30min C quenching and tempering 870℃/30min+500℃/30min G 950℃/30min+500℃/30min D hardening and tempering 870℃/30min+550℃/30min H 950℃/30min+550℃/30min Normalizing sample with the size of 130mm×150mm×15mm is cut from TMCP 15mm thick plate steel.
The reason is 950 ℃ hardening heating temperature is high so the hardening residual austenite is relatively high, with increasing tempering temperature of the residual austenite grain boundaries gradually in the tempered martensite decomposed into ferrite and cementite in tempered gradually dispersed, get the cementite and ferrite mixture gradually machinery at granular temper together form a certain amount of troostite by residual austenite decomposition.
Table2 The effect of normalizing temperature on the mechanical properties of EH36 number Yield strength Rel/MPa Tensile strength Rm/MPa Elongation A/% -40℃ impact Energy AKV/J hardness（HRC) Grain size scale A 385.2 541.1 22.7 56.5 36.8 9 B 370.2 496.3 25.6 87.6 52.5 9.5 C 352.6 467.6 25.3 70.1 47.6 10 D 371.1 493.6 27.6 89.5 57.1 10 E 372.5 496.7 27.6 91.2 64.1 10 F 381.2 507.5 28.7 95.4 43.1 10 G 382.6 517.2 30.6 121.1 56.3 10.5 H 384.6 516.3 32.2 142.6 55.5 11 4 Conclusions 1)Integrated thermal hardening and tempering treatment mechanical process for EH36 Steel's performance has greatly improved, and the optimization of the grain morphology, banded structure scatters pearlite, have very obvious affect. 2)For EH36 level of ship plate steel,hardening temperature is 910~950 ℃ between performance improvement is best, and the best tempering temperature about 550 ℃. 3) During 500~ 550 ℃,the lash performance of EH36 ship steel is better with the tempered temperature rising up.

The impact toughness can be improved by grain refinement, enhanced cleanliness of the steel, refinement and spheroidization of inclusions, and formation of intragranular ferrite on incusions, ect.
Titanium and calcium have been added for grain refinement in steels and for improving strength and toughness of steels welds [5,7,8,9].
The total numbers of the inclusion in Ti-Al deoxidised steel decreasing 32% after 60 minutes, but it is 0.5% in Ti-Mg treating steel.
Only the characters (such as total number, average diameter, dimension distribution, ect.) of inclusions are suitable, can the inclusions play a role in pinning of austenite growing and promoting of intergranular ferrite (IGF) [11].
So the inclusions in this sample are more effective to inhibit the austenite grain growing and to promote IGF formation.

Consequently the softening of the base alloy causes by the nitriding due to coarsening of the grain size, over aging and so on.
The mean grain size of the alloy was about 18μm.
A crack initiates in grain at specimen surface in both alloys.
Figs. 6 and 7 show crack growth curves and relation between crack length a and relative number of fatigue life N/Nf.
Φ4Φ4 Fig.1 Shape and dimension of specimen Fig.2 Microstructure of nitrided alloy Fig.3 Hardness distribution of nitrided alloy Specimen surface Compound layer 0 200 400 500 1000 1500 硬さ（ Hv） 表面からの深さ（μ m） Depth from specimen surface (μm) 10 5 10 6 107 10 8 0 200 400 600 800 1000 Stress amplitude, a(MPa) Number of cycles to failure, Nf (cycle) Aged Nitrided Fig.4 S-N curves of aged and nitrided alloys Detail of notch (a) Aged alloy (σ a=800MPa,Nf=6.82×104 cycles) Fig.5 Change in surface state of specimen due to stress repitetions ( Crack front) Fig.6 Crack growth curves Fig.7 Relation between crack length  and relative number of fatigue life N/Nf Fig.8 Relation between crack growth rate d/dN and crack length  N=0 (cycle) N=2.4×10 4 N=3.6×10 4 N=3.9×10 4 (b) Nitrided

It is prone to intradendritic segregation during casting process and greatly enriches peripheral regions of dendritic grains.
The charge was composed of aluminum (99.9 %), copper (99.9 %) and fine-grained double ligatures Al-Mn, Al-Zr, Al-Sc, Al-Si, Al-Fe and triple ligatures Al-B (Ti), Al-Cu-Mn.
Fine-grained ligatures were manufactured using known methods: the semi-continuous method of casting ingots of small diameter [18] or the crystallization under the pressure in a centrifugal mold method [19, 20].
Exposing to magnetic field was conducted in order to refine the grains and provide equigranularity along the volume of an ingot [14].
This can be seen in numbers in Table 5, where the Erichsen test results are presented.

Also, the number of peaks in the X-ray diffractograms increases with increase in thickness of the films.
It was found that there is a negligible increase in the grain size as the thickness of the films increases.
It is seen from table 1 that thin films with smaller grain size contain more dislocation density [27].
Interestingly, it is observed that with increase in thickness of the films, the number of additional peaks (fig. 2) increases before the fundamental absorption edge.
In case of polycrystalline films, extra absorption of light occurs at the grain boundaries.

One of the most difficult concepts to understand for the student is the grain flow caused by the process of hot plastic deformation.
The simulation of two cases showing different grain flows is presented.
The small corner radius of the stamps in that area makes impossible for the surrounding grains to flow parallel to the stamp boundary, leading to a poor grain flow.
Grain flow.
The number of variables governing this process is high.