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In addition, with more nano-carbides adding, the number of white core grains increases and that of black core grains decreases.
Furthermore, the number of white core grains increaseswith more nano-carbides adding, In cermet D there are many white core hard grains.
Apparently, crazy grain growth occurs in cermet C, or D with nano-micro carbides, where big grains ,up to 5 µm, and small grains less than 0.5 µm coexist, and the heterogeneous microstructure results in poor material performances.
Judging from the forming process of the three hard grains, it is apparent that the microstructure of white core grain is superior to black core grain in improving material performances, wing to much more homogeneous composition transition of different phases .
Furthermore, with the addition level of nano carbides increasing, the number of white core grains increases and that of black core grains decreases.

An average diameter of grains in Ti-alloy is about 3µm.
The numbers Ԙ㨪ԧ in the figure correspond to analyzed areas of composition, and the values obtained are tabulated in the inserted table (at%).
Journal Title and Volume Number (to be inserted by the publisher) change of the Ti-alloy substrate is shown in Fig. 4.
Discussion Miniaturization of Ti-alloy Grains.
Recrystallized grains must have little lattice defects.

Recently, CEC was successfully applied to few number of materials to produce ultra-fine grain structures such as AZ31 alloy[20], Mg–Zn–Y–Nd alloy [21] and AM60B magnesium alloy[19].
It is apparent from the observations in the present microstructures that the grain structure has been enhanced with CEC deformation due to reducing the grain size.
Small new grains are found in the CEC deformed structure after 2 pass, see Fig. 2(c).
Fig. 4 shows the hardness variation with the extruded Al-1Cu alloy with the number of CEC passes.
It is clear that the hardness is noticeably affected by the number of deformation passes.

The Consistent Description of Crack Developing Process based upon COTTRELLˊPiling up of Dislocations Model Aimin Yang Institute of Materials Science and Engineering, Xi`an Shiyou University, Xian, shanxi, 710065,china amyang@xsyu.edu.cn key words: Crack Nuclearation, Criterion Number, Fracture Toughness, Brittle Material Abstract.
Thus, the nuclearation life can not be determined, which is more important for some materials, such as high strength materials[2], most of their life come from the nuclear component.From the practical point of view, Manson and Hirschberg put forward [3] the "engineering crack size" concept, meaning through the 3 to 4 grains in the crack size range, 0.076 ~ 0.1mm on the fine grain or 0.1 ~ 0.25mm on the coarse grain, which can be considered as the crcack nuclearation size.
Now set ，Xp can be seen as Crack Nuclearation Criterion Number; when，crack nuclearation does not occur；when，crack nuclearation ocuurs；so the role of Xp is similar to Reynolds Number in fluid mechanics.
Crack Nuclearation Criterion Number Xp reflects the combined effects of stress field in crack tip and resistance of material to stress, which is more reasonable than the crack fracture toughness.
In this way, with the new concepts “Crack Criterion Number”, the parts of the crack Nuclearation and the part of the crack expansion can be clearly distinguished and described Conclusion 1）the crack Nuclearation capability of Material can be characterized with the crack Nuclearation touchness Kp，and when，the crack Nuclearation ocuurs； 2）Criterion Number Xc is suggusted for describing the different crack development steps for the brittle material: 3）Crack Nuclearation Toughness is 1/2 of Griffith Fracture Toughness for the brittle material..

To achieve this, all processes employed commercially today seek to initiate solidification with as large as possible a number of grain "nuclei," thereby achieving a high "grain density".
In some cases a strong grain refiner is employed to obtain the high grain density.
If they are sufficiently large in number and hence small in size, they will ripen, on isothermal holding or slow cooling, into a structure suitable for semi-solid forming with little entrapped eutectic.
Figure 2 is a summary plot for Al-Cu alloys of roughly 4 to 7wt% Cu; data are from a number of investigators assembled by Bower, Brody and Flemings [3], from Bardes and Flemings [4], and from Annavarapu and Doherty [5].
Quantitative dendrite coarsening models have been developed by a number of investigators; these have generally involved simple geometries.

Fine Grained Mortar (FGM) offers a new innovative technology binder system to strengthen or repair concrete structures.
The innovative technique is achieved by using a small maximum grain size of 1 mm for the mortars.
Fine Grained Mortar Fine grained mortar is a special binder system which is achieved by using a small maximum grain size of 0.6 mm to 1 mm.
Ongoing Studies Studies of the used of FA as a cement replacement in FGM have been reported by a number of researches.
Then were ground by grinder until 95% of the particles could pass trough sieve number 325 (45µm) complying the requirement of ASTM C618 [33].

The cyclic character of nucleation and growth of new grains during deformation results in a dynamically constant average grain size.
The nuclei of new grains appear as a result of local migration of original and/or strain-induced grain boundaries.
The numbers indicate the boundary misorientations in degrees.
The new fine grains evolved under warm working, therefore, are essentially the strain-induced largely misoriented (sub)grains.
Many annealing twins in new fine grains in Fig. 5a indicate the grain boundary migration.

Ga Penetration along the Grain Boundaries of Aluminum Alloys.
The Ga penetration process along grain boundaries of Al-based alloys while they are in contact with Ga containing aqueous solution was studied.
Currently, several known systems, in which the effect of fast penetration of liquid metal at the grain boundaries were observe are: Copper-Bismuth (Cu-Bi), Nickel-Bismuth (Ni-Bi), Aluminum-Gallium (Al-Ga).
The effect of embrittlement can be interesting as a method of preparation for grain boundary (GB) chemical composition study.
Acknowledgement This study was carried out with financial support of Ministry of Education and Science of Russian Federation (Co. 4.1963.2014/K) and Russian Foundation of Basic Research (Project 13-03-12191) with the use of the equipment of Common-Use Scientific Center‘‘Material Science and Metallurgy’’ at NUST ‘‘MISiS’’ (identification number RFMEFI59414X0007, agreement № 14.594.21.0007) References [1] R.S.

Meanwhile, a set of optimal craft parameters for preparing Co3O4 nanoparticles with smaller grain diameters was propounded and the effect of four process parameters mentioned above on grain diameter of resultant was figured out via 3D diagrams.
By maximizing it, the array w can be written in terms of the Lagrange multipliers and training samples as: (8) where, l is the number of SVs.
, itermax is total number of iterations.
In Table 1, each value in last column entitled Y is given by subtracting the value of grain diameter from 100nm.
It is found from Fig. 2 that the grain diameter is relatively larger under a higher concentration of Co(NO3)2 solution, in other words, the high concentration of Co(NO3)2 may result in agglomeration and grain diameter growth.

Introduction The necessity to produce lightweight components in an increasing number of industrial sectors is an important driving force for introduction of magnesium alloys.
One can also note that a way to increase the efficiency of ECAE processing is to reduce the temperature of processing with the number of extrusions.
From relation (2), one can predict the critical grain size for which, at a given temperature, grain boundary diffusion dominates.
At 350°C, a grain size of about 10 µm is predicted.
This increase was preferentially attributed to strain induced cavity nucleation rather than cavity growth since the mean cavity diameter remained roughly constant whereas the number of cavities per mm3 noticeably increased [14].