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This research looks at the recovery and recrystallization processes during annealing after cryo-rolling, and compares the formation of sub-grains and recrystallized grains to those where rolling was performed at room temperature.
During subsequent annealing, the driving force for recrystallization is increased with a decrease in the rolling temperature, with the cryo-rolled material having a greater number of nucleation seed and consequently, a fine grained recrystallized microstructure.
The 75% cryo-rolled sample displays flat, elongated grains and shows a hardness of 50HV, while the 75% cold rolled sample shows a less-distorted grain morphology and has a hardness of 47HV.
Recrystallized grain is circled.
This UFG structure does still contain cell boundaries within some of the grains.

Results In Fig 1, the ratio κGB / κV (where κGB and κV are, respectively, the positron trapping rates in defects at grain boundaries and in defects within the grain) is plotted as a function of the specific surface of the grain sGB = 3/R, were R is the radius of the grain assumed spherical.
The ratio of positron trapping rates κGB / κV into defects at grain boundaries and into vacancies inside grains versus specific surface of grains (●: single crystal, ○: pure sintered samples, ♦: doped sintered samples).
According to the trapping model, the ratio κGB / κV = α . cGB / cV, where α is a dimensionless constant and cGB and cV express, respectively, the fraction of positron traps at grain boundaries and within the grains.
Furthermore, this correlation also expresses the dependence of the dielectric breakdown strength on the specific surface of the grains (i.e., the number of sites that are available for segregation and which are contained in the investigated volume of the sample) as well as on the fraction positron traps at grain boundaries.
This behaviour can be attributed to the segregation of Si at grain boundaries.

It was shown the great scattering of triple product values, measured for different grain boundaries (GB) at the same samples.
Introduction Diffusion along grain boundary is one of the important processes, which occurred in polycrystalline materials.
Special attention in this paper is paid to the distribution of GBD triple product value for different grain boundaries.
On Fig.3a the numbers of GB triple product values at the temperature 400 °C for the groups are shown.
The alloy, containing 0.1 % Ce is characterized by much smaller grain size (less than 100 mm) than for pure Al and Al-Cu alloy (about 500-1000 mm) and thus the number of P values measured for the samples are 5 times larger.

With the increase of deformation degree, the number of shear bands increased.
A few small grains about 20 μm were found in the grains about 50μm.
A large number of slip bands were found in the grains.
The small grains have been found in the grain boundaries.
A large number of recrystallized grains exists in the upper area and edge of large grains in middle area.

The refinement of grain always companies the refinement of Si particles.
Vast number of finer TiAl3 and TiC particles can be in situ precipitated from melt and homogeneously distributed in melt, which results in the low-Ti aluminum alloys billets being self-refined into the fine equiaxed grain.
When remelted it to produced alloys, high number of the intrinsic TiAl3 and TiC particles existed in low-Ti Al alloys billets are transmitted to A356 melt.
The restricting effect of Ti on the α-Al grain growth is very larger.
The testing A356 alloys have the excellent grain refinement effect and fading resistance.

When adding 20% iron grains, due to the large size of iron grains, with the gas flow quantity added from the bottom increasing, the binding force between the iron grains gradually weakened.
When adding 20% iron grains, the movement structure of gas quenched slag steel and iron grains in the bubbling state is the simplest because of the balance of force.
When the material is added with 20% iron grains, the average size of grain composition increases, and the porosity of material layer increases.
Remf = [C12+C2Ar] 1/2-C1 (1) Remf —critical reynolds number; C1=33.7; C2=0.0408.
If the layer thickness is 300mm, the critical fluidization pressure difference between before adding iron grains and after adding iron grains is about 1kPa.

The results show that the number of Nd element in the AZ91 magnesium alloy has effect on the grain refining efficiency, and the granular or acicular Al3Nd phase precipitate in matrix.The corrosion products of the AZ91-0.4%Nd alloy mainly composed of Mg(OH)2 and Al.
When the chemical composition and corrosion medium have relatively fixed, the grain size of α-Mg phase, the number of β-Mg17Al12 phase and its distribution have greatly impact on the corrosion of magnesium alloys, particularly AZ91 alloy [6,7].
Most of β-Mg17Al12 phase distributed along the grain boundaries transformed into granular, the grain size of α-Mg refined and the granular or acicular Al3Nd phase precipitated in matrix.
So, the number of Nd element in the AZ91 magnesium alloy has effect on the grain refining efficiency.
%NaCl solution for 8 days Conclusions The number of Nd element in the AZ91 magnesium alloy has effect on the grain refining efficiency, and the granular or acicular Al3Nd phase precipitate in matrix.The corrosion products of the AZ91-0.4%Nd alloy mainly composed of Mg(OH)2 and Al.

Single grains on both sides of the low angle grain boundary were parallel to the [001] direction.
If the amount of γ’ phases on both sides of grain boundary were similar, the grain boundary will in the middle of the two dendritic grains arms; otherwise, the boundary was between the dendritic grains arms and the inter-dendritic space.
Besides, the grain boundary turned into prominent as the increase of the angle of the grain boundary.
The empirical equations for determination are: Cr at%/(Cr+Mo+0.7W)at%<0.72 (1) Cr at%/(Cr+Mo+0.7W)at%>0.82 (2) It could be determined as MC6 or M23C6 if the number fits equation (1) or (2) correspondently.
However, if the number is between 0.72-0.82, the result relates to the technology of heat treatment.

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.

A thin dilution zone with a thickness of 50 µm is observed at the interface, and consists of a few TiB and TiC and a large number of lamella grains in which a thin needle-shaped martensitic microstructure is exist.
There is a dilution zone with a thickness of 50 µm at the interface, and is composed of a large number of lamella phase growing perpendicular to the substrate.
The interface morphology in a high magnification is shown in Fig.4 (d). a few fine TiB and TiC are present in lamella grain boundaries, and a thin needle-shaped martensitic structure is formed within lamella grains.
Subsequently, a eutectic microstructure in which TiB and TiC are embedded is formed along lamella grain boundaries.
A thin dilution zone with a thickness of 50 µm is formed at the interface, and consists of a few TiB and TiC and a large number of lamella grains in which a thin needle-shaped microstructure is exist by a martensitic transformation. 2.