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In external parts there distributed a large number of fine eutectic microstructures, surrounded by a number of t-ZrO2 spherical grains, as shown by the arrow in Fig. 4, within the eutectic the t-ZrO2 micro-nanocrystalline fibers were universally observed to be embedded in α-Al2O3 matrix with a triangular symmetry of about 120°, as shown in Fig. 5.
Otherwise, in central parts there were a number of fine t-ZrO2 white spherical crystals, as shown by D in Fig. 6.
SEM images of crack propagation paths at external part of the ceramics showed there were two fracture modes, i.e. fracture in the eutectics and along the eutectics, as shown in Fig. 7, whereas at central part there was the classic transcrystalline fracture of ZrO2 grains, as shown in Fig. 8.
As the crack propagates at cerntral part of the ceramics, as discussed above, the ceramics matrix transforms a number of fine spherical ZrO2 crystals, the intensive coupled toughening mechanism of transformation toughening and micrack toughening is induced, as shown in Fig. 8, resulting in the highest fracture toughness at central part of the ceramics.
XRD, SEM and EDS results showed there were different microstructures in the ceramics of a large number of fine Al2O3-ZrO2 eutectic microstructures at external part and fine spherical ZrO2 crystals at central part of the ceramics.

Introduction In recent years, ultrafine-grained (UFG) materials prepared by the equal channel angular pressing (ECAP) technology have been attracting more and more interests of research, owing to their unique mechanical behaviors [1-4].
It can be seen from Fig. 1(a) that a large number of small S-precipitates (AlCuMg) uniformly distribute in the as-cast sample, which have contributed to a remarkable strengthening effect on the alloy, as evidenced by the compressive stress-strain curves presented in Fig. 2.
As the cast sample of the LY12 Al alloy is directly deformed by ECAP for 2 passages, the grain is obviously refined and the high-density dislocations are significantly induced (see Fig. 1c).
Meanwhile, a large number of small S-phases in the process of ECAP are dissolved into the matrix, and the precipitation-strengthening effect is thus weakened.
It should be noted that the cracks mainly form along grain boundaries (GBs) making an angle of ~45° with the stress axis for the annealed sample.

The microstructure consists of recrystallized grains and dispersed secondary phase particles.
Finer grains were obtained for the sheets of higher iron content.
Grain size is comparable among these sheets, with the exception of the 50t mold products with 1.0%Fe, which exhibited larger grains.
For the 50t mold cast products containing 1.0wt% iron, the number of coarse particles around 10μm was outstandingly high.
[5] M.Asano, et al., Journal of Japan Institute of Light Metals, Vol.52, No.10(2002), p.448. 1 10 100 1000 10000 100000 0 5 10 15 20 25 Diameter of secondary phase particles, µｍ Number of secondary phase particles, /mm2 HSTRC (0.2Fe) 5t mold cast (0.2Fe) 50t mold cast (0.2Fe) HSTRC (1.0Fe) 5t mold cast (1.0Fe) 50t mold cast (1.0Fe)

Grain size of limestones was 5 to 10 mm.
Target size of grains was <0.3 mm.
Samples A and G, however, have a significant number of pores, in particular limestone G has nearly 30% porosity.
Grain size between 20 and 40 µm were used to minimize impact of porosity.
Acknowledgements This work was financially supported by project number: 15-08755S “Study of effects of samples preparation on inorganic binders’ final properties”, project number FAST-J-16-3734 “Study of influence of limestone properties on final properties of lime” and project No.

The abrasive grains supplied into the machining zone were SiC.
It can be expressed as, (5) where n is the number of process responses.
Grain size (Gs) [mesh] 180 220 320 F.
The results show that the experiment number 10 has the largest grey relational grade.
n0 : The number of significant process variables

While the biggest problem of the ultra-precision grinding is that the grain which breaks off from the grinding wheel would embed the crystal surface [4-8].
From the Fig.4 (b), one of the biggest nick is measured by the measure-tool of VHX-500, the nick width is 46.0µm, the depth is 5.7µm, compare with the granularity of the grinding wheel (the granularity of resin-bond diamond wheel of W20 is 20µm) can get, there are many reasons due to the bringing of nicks, both bigger granularity grain of wheel grinding on crystal surface and grinding-bits skidding between wheel and KDP crystal surface are possible.
In precision and ultra-precision grinding, we should elect the grinding wheel of well-proportioned and small grain granularity together with the filtration of grinding-liquid synchronously in order to avoid damages.
Compare the Fig.5 with fig6, the position of the characteristic peak excurses toward the high wave-number, basis the presses stress can cause the Raman spectrum excurse toward a higher wave-number, the pull stress can cause the Raman spectrum excurse toward a low wave-number, so there are press stress in the grinding surface of KDP crystal, the sketch map is shown in Fig.7.
(4) In precision and ultra-precision grinding, elect the grinding wheel of well-proportioned together with small grain granularity in order to get higher quality surface of KDP crystal.

Currently, a number of these materials can be found easily in the market.
The solid-state reaction had been reported [1-3] whilst the wet chemical reaction was carried out by a number of researchers [4-7].
The powders are clearly agglomerated but there is clearly a subtantial grain growth from a grain size of approximately 200nm at (900oC) to 1mm and 2mm (about 5 to 10 times) at 1000oC and 1100oC, respectively.
As the temperature is further increased to 1300oC, an apparently exaggerated grain growth is observed, i.e. 8mm (about 40 times magnification), even though the phase remains stable as a single-phase β-TCP .
Henceforth, it is proven that under the parameters adopted in this work, the β-TCP phase formed remains thermally stable up to 1300oC with an accompanying agglomerated grain growth.

The research[6] shows that when the sintering temperature is higher than 1400oC, gamma-TiAl alloy’s density will decrease because the grain becomes coarser.
The parameters were set as following: the initial population number N=100, the cross probability Pc=0.8, the mutation probability Pm=0.08, and the error e=1E-8.
XRD spectra of the alloy prepared under the optimized condition The volume fraction (Vk) of each phase(k) was calculated from the peaks according to the following formula[6]: (1) where ρ is the density, n is the number of lattice planes used for calculation, and the values of I are the intensities of the diffraction peaks.
As shown in Figure 6, under the condition of 1391oC，291min and 37 MPa, fully lamellar structure contained fine grains and some coarse grains was obtained from the sample that was not treated at all.
The average size of the fully lamellar grain was about 90μm.

Firstly, the chemical composition of the fine grain steel slag is analyzed by spectral analysis test.
Table 7 Forecast traffic composition Front axle load [kN] Back axle load [kN] Back axle number Number of rear wheel group Back axle wheelbase [m] Traffic   29.3 48.0 1 2 0 300 58.6 114.0 1 2 0 400 45.1 101.5 1 2 0 400 31.3 78.0 3 2 4m 300 23.1 73.2 2 2 4m 400 26.5 56.7 2 2 2m 400 Pavement structure design.The pavement structure is considered to be 3-layer system.
Material of the surface layer is asphalt concrete, including fine-grained asphalt concrete（FGAC）, mid-grained asphalt concrete（MGAC） and coarse particle asphalt concrete（CPAC）.

The experimental results have shown that the deep cryogenic treatment causesβphase of alloy to disperse and makes the grain smaller than that of joint before deep cryogenic treatment.
Because grain boundary specific surface area of small α(Al) is large, the tensile strength of welded joint is increased.
Table2 Tensile properties for 5A06 welded joint before and after deep cryogenic treatment Sample number Fracture location Tensile strength σb / MPa Yield strength σs / Mpa Elongation δ % Before treatment WZ 333.35 228.16 7.05 -155˚{TTP}730 C，4h WZ 335.50 228.79 15.74 -155˚{TTP}730 C，8h HAZ 345.89 243.39 16.70 -155˚{TTP}730 C,10h HAZ 354.16 257.39 18.03 Hardness assay.
Grains of deep cryogenic treatment welded joints are finer than that of non-deep cryogenic treatment joints