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Grains shape and array model 1.
Computational model of CHTC (hf) based on “grain state”.
The Reynolds number, Re, and the Prandtl number, Pr can be determined by Eq. (11) and Eq. (12)
Based on the simulation tangential grinding force of single grain, and from Eq. (22) and (23) [11], we can conclude the simulation tangential grinding force of more grains with the grain grit 70#, shown in Table 4
(22) Where Fts andFtm are the simulation tangential grinding force of single grain and more grains respectively, and Nt is the active number of grains per unit area, expressed as Eq. (28) [11]

Introduction Nanocrystalline alloys are composed of grains in nanometer scale (typically < 100 nm) and a large number of grain boundaries.
The grain boundary diffusivities of Cu in a severe-plastic-deformation-generated nanocrystalline nickel with a grain size of ~ 300 nm are ~4-5 orders of magnitude higher than those in the coarse-grained nickel [2].
For comparison, the nitriding was also conducted in the same processing condition on a coarse-grained Ni-10 Cr alloy (mean grain size: ~ 36 µm).
Clearly, the Ni-CeO2 nanocomposite was nano-grained with an average grain size of ~50 nm (Fig. 1a), while the electrolytic Ni was submicro-grained with a mean grain size of ~0.5 µm (Fig. 1b).
Such a high number density of nanoparticles dispersed in the nanocomposite would significantly increase the numbers for CrN nucleation.

An average prior β grain size of approximately 350µm was obtained at 1060°C, although grains on the order of ~800µm were also observed.
The αp grains, which are located at prior β grain boundaries, appear to significantly retard β grain growth resulting in a relatively fine β grain size similar to the as-received material.
However, a limited number of samples tested at this temperature displayed only minor amounts (<5%) of αp, which was possibly a result of test-to-test variations in actual sample and/or test conditions.
At the center of specimens, original prior β grains are elongated transverse to the compression axis with grain boundaries displaying a wavy nature.
The limited number of dynamic recrystallized grains is consistent with the favourable recovery characteristics of the bcc crystal structure.

Because of the plastic agent, the number of active abrasives will increase and the abrasive cutting depth will become even and small [1].
According to study cutting depth distribution of abrasive grains in SFAP lapping by X.
Lv [2], sizes of abrasive grains, concentration of SFB bond and processing load were the important factors on the abrasive grains cutting depth distribution.
(1) where, The different cutting depth of abrasive grains was mainly due to the different grit size of abrasive grains.
The reason of deviation was that microstructure of 4000# SFAP was complex for greater number of abrasive grains.

The average grain size of AZ91D alloy is about 40μm.
(1) Where σr is fatigue strength; k is the numbers of coupled reverse results; m is the stress level series; n is the efficient specimen numbers which can be coupled; σj is the fatigue strength at No. j grade stress level; σi is the stress value at No. i grade stress level; υi is the specimen numbers at No. i grade stress level.
The fatigue crack is propagated along grain boundary as well as transgranular form.
The facet sizes are nearly the same as, or smaller than, the average grain size.
Fatigue cracks of AZ91D alloy initiate principally at inclusions of alloy subsurface, and propagate along the grain boundary.

In actuator applications, the SMAs are subjected to large number of thermo-mechanical cycling which introduces defects in the material.
Fine scale grains, few tens of nanometer in size, can be seen in good contrast.
It can be noted that large number of thermo-mechanical cycles resulted in deformation bands with fragmented twinned lath structure and significant de-twinned regions.
As the number of cycles increases, the martensite variant intersections loose coherency.
On TMC, the material develops well defined martensite variants/grains.

Lower calcining temperature and inadequacy of holding time led to an incomplete combustion of organic matter, which result in, a large number of pore entraining into BSPT ceramic when sintering.
Grain growth was apparent during the first heating step, as temperature rising, the rate of grain boundary Fig. 3.
Analysis of grain size effect.
The trend of grain size effect was shown in figure 8.
The trend of grain size effect of BSPT bulks.

The atomic number contrast afforded by BSE imaging displays that the secondary phases with bright contrast contain elements with higher atomic numbers than α-Mg.
A great number of second phases are precipitated in the alloy with Zn addition increasing.
It is noted that a great number of Mg12ZnEr phases with 18R LPSO structure precipitate at grain boundaries.
The LPSO phase possesses excellent plasticity and toughness, so it can relieve a large number of local strains and lead to a relatively homogeneous plastic deformation[15].
The addition of Zn effectively decreases the grain size of as-cast alloys

Electrochemical corrosion behavior of Cu-20Fe-12Cr alloys with the different grain size in solutions containing chloride ions Zhongqiu Cao, Rong Xue, Jing Bian, and Yajun Fu College of Chemistry and Life Science, Shenyang Normal University, Huanghe Northern Street 253, Shenyang, Liaoning Province, China Email: caozhongqiu6508@sina.com Keywords: Fe-Cu-Cr alloy; grain size; electrochemical corrosion Abstract.
The corrosion rates of MACu-20Fe-12Cr alloy become faster than those of PMCu-20Fe-12Cr alloy because the reduction in the grain size of MACu-20Fe-12Cr alloy produces large concentrations of grain boundaries.
MA Cu-20Fe-12Cr alloy has more homogeneous microstructure and is able to produce large concentrations of grain boundaries in the course of reduction in grain size by mechanically alloying.
Atom in grain boundaries is arranged irregularly and its lattice distortional energy increases, grain boundaries have trend to decrease their energy automatically.
(3) The corrosion rates of MACu-20Fe-12Cr alloy become faster than that of PMCu-20Fe-12Cr alloy because the reduction in the grain size of MACu-20Fe-12Cr alloy produces large concentrations of grain boundaries and increases the number of reactive atoms in alloy surface.

A large number of intragranular pores and a small number of overall pores was observed in Ca-PSZ, resulting in this material having the lowest bulk density.
The grain size of Ca-PSZ is non-uniform, and most of the grains, those with an average grain diameter of around 6 μm, are densely packed, however, there are also some irregular grains, with an average grain diameter of around 10 μm, and a large number of pores, resulting in the low bulk density of the material.
The average grain size of Mg-PSZ is larger, with an average grain diameter of around 7 μm, and the grain shape is irregular.
Y-PSZ has a uniform grain size, with an average grain diameter of around 5 μm, and sharp edges.
No abnormal grain growth was observed for the sample, the grain bonding is compact, and a small number of pores exist in the material.