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Attempts have been made by researchers to develop coating technologies for powder grains.
The matrix materials coated were TiC powders with a grain size of 0.5-1.0 µm.
The uniform coatings will not only stop the grains from growing during the fabrication process, hence maintaining the hardness of the grains, but also increase the hardness of the grain surfaces.
Nevertheless, some voids (or air cavities) along the grain boundaries and grain aggregations due to ineffective dispersion can be observed for the new ceramics in Figs.2a and b.
A SEM observation on the fractured surfaces of the new tool materials has shown that each carbide grain has been uniformly coated with a layer of alumina and/or silicon dioxide, and the new materials have a more homogeneous microstructure than those fabricated using Journal Title and Volume Number (to be inserted by the publisher) 25 the conventional method.

After compared the DOS of these different structure types, the results show that the discrepancy in structural stability of carbides can be attributed to the difference in the bonding electron numbers at Feimi level.
Introduction The effect of niobium in steel is realized by grain refinement and precipitation strengthening for strengthening and toughening, at the same time the dissolved niobium can enhance hardenability, and delays phase transition from austenite to ferrite.
Through the electronic number N(EF) at the Fermi level EF to the total density of state about the average each atom of different structure to judge their valence electron structure activity.
Namely the less Eelectron number is, when external conditions change, the smaller crystal electronic structure probability change, so the higher the corresponding phase structure stability[12].
Therefore, in medium and high carbon steel, NbC is more easily precipitate than Iron carbides, still has grain refinement and precipitation strengthening effect.

Therefore, much attention has been increasingly paid on semisolid metal (SSM) processing, which is characterized by a number of advantages, such as low porosity, heat treatability, consistency and soundness of mechanical properties, the ability to make complex component shapes and longer die life [2].
It can be seen from the figures that, in the case of HPDC, when pouring temperature is at 660°C, microstructures of test samples are made of coarse and dendritic grains; when pouring temperature at 630°C is near to the alloy liquidus, the microstructures are similar to that of commonly low superheat pouring case, its grain morphology is fine, rosette-like but not uniform.
When processed by the modified MSCP, a uniformly fine, globular Si grains can be obtained as shown in Fig. 4(b), and its mean grain size of primary phase Si is less than 30µm.
(a) (b) In the conventional casting processes, heterogeneous nucleation takes place from the mould wall, and then columnar grains increase progressively as solidification proceeds, since those grains which have a preferred growth direction oriented near the heat flow direction tend to "crowd out" less favorably oriented grains [9], thus solidification structures are not homogeneous.
It not only increases the amount of potential nucleation agents, but also disperses the cluster of potential nucleation agents, giving rise to an increased number of potential nucleation sites.

Particular attention is paid to the form factor of solid grains.
Essential requirements for thixoforming materials with h - viscosity, k - constant, g - shear velocity, n - Oswald-de Waele exponent; dm - mean grain diameter, f - forming factor, A - grain surface area, U - circumference of a grain, SSS - the grain boundary surface area between the solid phase, i.e. the surface area between the cohering grains not separated melt, SSL - phase boundary surface area between solid phase and melt, dT - melt range, f(c, T, p) - function of (alloying element content, rate of cooling, pressure), fS - proportion of solid material, TM - melt temperature of a component; TL - liquidus temperature; p - exponent defined by the phase state equilibria.
The increase in the liquid phase fraction, calculated based on Scheil equation for a number of aluminum alloys, is shown in Fig. 4a and Fig. 4b.
Thus, according to the initial estimate determined by the factors Fα and Dm, the billets obtained by casting using a water-cooled slope represent a product of the required quality in terms of grain size and morphological features, suitable for processing by thixotropic forming methods.
The number of structural components including the amount of structurally free liquids required for high-quality forming of parts from alloys that are compositionally close to eutectic, may be provided through the use of the conditions of thixobillet formation that are far from equilibrium only as the solid phase at the stage of equilibrium solidification of a thixobillet reaches ≈ 50 %.

It can be seen that grains and carbide fragments are elongated along the stress direction in all the samples, while the deformation of microstructure increases with creep time.
Some viewed that creep holes nucleate by grain boundary slide, while other attributed the nucleation to the separation of second phase particles from matrix.
In this paper, band of cavities forms along the grain boundaries after creep for 152.5h, in the condition of 450oC /320MPa(Fig.5c).
The shedding of coarsened carbide at sliding grain boundaries during creep promotes the nucleation of cavities.
It can be inferred that the temperature of 450oC is not high enough to stimulate large number of dislocation climbing for non-quenched and tempered steel.

The numbers in the graph were obtained using EBSD analysis and the details are presented in [5].
In the sample heated at rate of 60 K/s, mostly sub-grains are formed in the formerly deformed ferrite grains, and the cementite is not completely dissolved at 775 ºC. 3 K/s 60 K/s 750 ºC 775 ºC Fig. 2.
The ferrite grain size is similar, but the appearance of ferrite grains is changed.
At 780 °C annealing temperature the ferrite appear clearly delimited from each other and the martensite is mainly dispersed at the grain boundaries, whereas at 840°C annealing temperature boundaries between ferrite grains are no longer so keen to identify and martensite and bainite is embedded in these ferrite grains.
[5] Property oriented design of hard constituent hardness and morphology in continuously annealed/galvanized DP sheets – VADPSheets – Contract Number: RFSR-CT-2011-00014

The friction coefficient for different thickness layers are presented in Fig.3 as a function of number of cycles.
Fig.3 Friction coefficient of three layers against Si3N4 ball as a function of the number of cycles: (a) inner layer, (b) surface layer.
On the worn surface a large number of the wear particles and ploughing grooves are observed by SEM.
The particles in the surface layer were repeatedly crushed into fine-grained wear particles, some of which subsequently ploughed the contact surface as abrasive grain during wear process.
The surface layer has high friction coefficient, due to the coarse grained and porous structure, and its relatively high weight losses help to avoid the initiation of the fatigue cracks.

Our country is rich in mineral resources, in the full utilization of mineral resource service society construction at the same time; a large number of mineral resources exploitation also brought an incredible amount of tailings.
Every year because of a large accumulation of tailings discharge by the cultivated land occupied, environmental pollution and casualty case for infinite in number.
Table 1 and Table 2 respectively is MiaoGou iron ore concentrator, Luan County cherry blossoms iron ore tailings concentrator grain size analysis form.
Table 2 Luan County cherry blossoms iron ore tailings concentrator grain size analysis form Grain of level（mm） +0.074 -0.074～+0.056 -0.056～+0.037 -0.037～+0.019 -0.019 Production rate（%） 31.04 19.47 17.04 14.60 17.85 Luan County cherry blossoms tailings tailing grain average particle size is 0.0978mm, tailings of median diameter of 0.028mm.
Table 5 Test the mortar material used Serial number Water Cement Sand Tail ore Stone B-01 185 330 718 0 1172 B-02 269 330 304 414 1172 B-03 275 330 235 483 1172 Table 6 Tail ore concrete compressive strength and workability Serial number Tail ore replace rate (%) Water cement ratio Collapsibility (mm) Compressive strength (MPa) Concrete workability 7d 28d B-01 0 0.56 80 27.2 30.1 Good liquidity and cohesiveness, no secrete water B-02 60 0.86 80 26.6 37.4 A bit poor liquidity, common cohesiveness, secrete water B-03 70 0.88 80 21.3 27.4 A bit poor liquidity, common cohesiveness, secrete water The tail in the ore contains a certain amount of cement a reduced secrete water and the problem of segregation, and limestone and cement and water formed the paste, improve the concrete workability.

Temperature dependence of dielectric constant of barium titanate of different grain size [13] 2.
Some dopants inhibit grain growth and small grain ferroelectric ceramics exhibit high dielectric constant (Fig. 4) [14].
A large number of these compounds were found to be ferroelectric, some with very high Curie temperatures, e.g.
Numbers next to additive element indicate the mole percent addition [22].
(right) (dashes) grain size (solid line) conductivity of Nb doped BaTiO3 ceramics [23].

Elongated ferrite grains were accompanied by practically uniform distribution of pearlite.
Elongated ferrite grains were observed along perpendicular direction to the compression axis and small quantity of pearlite were distinguishable.
Basing upon a number of TEM observations, one may conclude that the effect described above is the most essential feature of the localized nucleation of cementite.
TEM examination of the sample structure also revealed dispersed precipitates within the ferrite grains.
Elongated ferrite grains, decorated with Fe3C particles, were considered to be the sole effect of preferential nucleation of carbides at localized flow bands.