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The formed chromium nitrides are different with big chromium carbides aggregating at grain boundary.
After nitride precipitation, the Cr diffusion distance shorten, thus, avoiding chromium depletion and grain boundary corrosion.
Thus, it can reduce chromium carbide formation and Cr depletion, and increase the grain boundary corrosion resistance.
After 1120 cycles testing, the sample surfaces welded by 1Cr13 have worse crack condition, more crack number and average crack length, no matter of average crack number, average depth and maximum crack depth of each surface on the three cross sections.
It will highly decrease the possibility of grain boundary corrosion, restrain crack source and improve heat-fatigue resistance.

Influence of the type of sand on sand concrete strength (numbers of sands according to the Table 1).
Concrete mixes, lying in this area, are characterized by a significant presence of aggregate to aggregate contacts (3-rd type contact), the number of which decreases when approaching the extreme point.
This is also consistent with the postulate, that the value ΔRmax is achieved when ensuring the maximum number of 2-nd type contacts.
Dependence of the sand concrete strength with different types of sand on the thickness of the coating of sand grains.
The strength of sand concrete depends on the type of sand, its voidness and specific surface, as well as cement grains graduation.

Thus, these addition elements can harden the Mg grains at high temperatures; but, more importantly, modify the b phase and its detrimental effect on grain boundary creep.
These small increments of reduction of large grained stock limit the ability to refine grain size and to refine eutectic intermetallic size.
Nanometer grain sizes as small as 700 nm are generated by TTMP (see Figure 4).
Elongated grains (A) and nanoscale α-Mg and β grains (B) found in transmission electron micrograph of the as-TTMP condition of AZ61L [Berman-21].
U.S Patent Numbers 4,694,882, 4,964,881, 5,040,589, Dow Chemical Company

The ordered arrangement types of grains on end face grinding wheel can be divided into phyllotactic, staggered and array pattern.
For staggered arrangement of abrasive grinding wheel, if the average number on circumference of the gains is I and radial direction J, the polar equation of abrasive grain is shown in Eq.2
Using the grains with rectangular pyramid shape for simulation, the abrasive grain M is 70/80, and the average cone angle is set for 80 degree.
Development of a superabrasive grinding wheel with defined grain structure using kinematic simulation.
Simulation for optimizing grain pattern on Engineered Grinding Tools.

XRD, FESEM and EDS results showed the ceramic coating was composed of a number of fine TiB2 platelets, irregular TiC grains and a few of Cr metallic binder and the inclusions of Al2O3 partilces, and physical and mechanical properties showed density, relative density, microhardness and fracture toughness of the ceramic coating were 4.25 g · cm-3, 98.2%, 24.6 GPa and 14.5 ± 3.5 MPa · m0.5, respectively.
A number of surface modification techniques has been attempted to fabricate this kind of coating.
Recently, large-bulk fined-grained TiC-TiB2 composites are achieved by a novel process called as combustion synthesis in high-gravity field [10], and the experiment is renewed by adjusting the composition of combustion system in order to achieve ceramic coating of TiC-TiB2 on 1Cr18Ni9Ti substrate by fusion bonding.
FESEM images and EDS results showed a large number of randomly-orientated, fine TiB2 platelets (presented by the dark areas in Fig. 2) were uniformly embedded in the irregular TiC grains (presented by the grey areas in Fig. 2) and Cr metallic phases (presented by the white areas in Fig. 2), and a few inclusions of α-Al2O3 black particles were also observed, as shown by the arrow in Fig. 2.
XRD, FESEM and EDS results showed the ceramic coating was composed of a number of fine TiB2 platelets, irregular TiC grains and a few of Cr metallic binder and the inclusions of Al2O3 partilces, and physical and mechanical properties showed density, relative density, microhardness and fracture toughness of the ceramic coating were 4.25 g · cm-3, 98.2%, 24.6 GPa and 14.5 ± 3.5 MPa · m0.5, respectively.

Equal-channel angular pressing (ECAP) is one of the methods of severe plastic deformation for producing ultra fine-grained material.
During the multi-pass ECAP process the accumulated plastic deformation creates microstructure of equiaxed fine grains with high angle grain boundaries.
The modelling results of annealed pore cooper workpieces demonstrate the even-numbered passes can be reach more homogeneous distribution than odd numbered ones.
During the simulation number of elements reached 5000.
On other interesting result from the simulation is the even-numbered passes can reach more homogeneous strain field than at odd numbered ones (see Fig. 5-7).

The tensile strength increased with the number of the ECAP passes.
For Cu-5.7%Cr and Cu-12.4%Cr alloys after four ECAP passes, the pancake shaped grains with well-defined boundaries have been developed in Fig. 2(b) and (c), and the width of lamellar grains has been about 150 nm or less.
The SAD pattern is a diffused ring-like pattern with extra spots, indicating that the ultrafine grain structure with high-angle boundaries is generated.
With an increase of the ECAP passes, lamellar grains nearly disappear instead of equiaxed grains with non-distinct boundaries, indicating the presence of high internal stresses created by high-energy non-equilibrium grain boundaries.
Horita, Using equal-channel angular pressing for refining grain size, JOM 52 (2000) 30-33

Chlorite distributes on the surface of detrital grains with being dispersive or collective, whose chips vertically grow on the surface of detrital grains.
Finally, a large number of residual intergranular pore and intergranular pore appear.
These clay minerals fill the pore and cover on the surface of grains.
Chlorite distributes on the surface of detrital grains with being chlorite cladding.
A large number of the interstratified minerals is hair-like or filar-like.

Wear testing instrument is expensive and scarce in number.
This condition indicates that graphite grains penetrating into wheel specimen surface are not too large in number, as can be seen from the not too thick black color of wheel specimen surface.
With the decreased number of graphite grains penetrating into the fissures of two contact field surface, the coarseness of surface has not been covered completely by the grains, so that the temperature of contact plane increases due to the energy loss on the material surface, and the wear level seems to be higher than that in previous experiment.
The microstructure shown in Fig. 5.b, through SEM test, reveals that the number of metal splinters seems to be larger than that of graphite splinters.
It indicates that the effectiveness of graphite splinters decreases, as graphite polishing decreases so that the number of graphite grains penetrating into the fissures of wheel specimen surface also decreases, thereby affecting the wheel’s wear level.

Addition of Ni powder prohibited the grain growth of the Ba2TiO4 ceramic.
Ba2TiO4 powders with Ni addition made the porous body of fine grains after 100 cycles, but Ba2TiO4 advanced the close packed body of the grain growth. 0 5 10 15 20 0 5 10 15 20 25 Ｔｉｍｅ　/h Weight /% 0 300 600 900 1200Temp
For Ba2TiO4 powders with Ni addition, the fine particles of Ba2TiO4 maintained a porous body of fine grains even after large number of cycles.
But the sintering advances as a result of grain growth in the case for Ba2TiO4 powders with no Ni addition.