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Numbers of ways have been developed for improving the strength of ceramic foams which are found in patents [2-4] and in articles [5-7].
Influence of composition on mechanical properties and the mullite grains morphology.
In the sample with higher alumina content (a7) no trace of elongated mullite grains could be observed.
Meanwhile, aspect ratio of mullite grains decreased with increase in alumina concentration, because alumina particles among the mullite grain boundaries restrain grain growth.
All the commutations in mechanical strength were also attributed to the changes in the grain morphology and grain size of the solid phases, which were predominantly influenced by the composition.

However, due to the limited number of slip systems available for plastic deformation at room temperature, their production by conventional thermal mechanical processing is inefficient and expensive [1,2].
Warm rolling and subsequent annealing have been performed on TRC strips to obtain fine equiaxed grains.
Another simple technique to obtain fine grain structure is to add grain refiners (GR), which works well for most casting processes.
The TRC strip (Fig. 2a) had a coarse dendritic columnar grain structure with an average grain size of 600 mm.
Barnett, Fine grained AZ31 produced by conventional thermo-mechanical processing, J.

Recently, a number of solutions were proposed to overcome the corrosion problems, like polymer films [7] and aluminium alloyed coatings [8].
The reduced grain size is a necessary condition for achieving the superplastic behaviour.
It is clear that the grain refinement effects of the process are evident.
In the nugget zone it is impossible to distinguish the grain boundaries while on the unprocessed side the grain boundaries are easily distinguishable.
In the FE model, the complex shape of the FS Processed zone, that is a cone-like zone with small equiaxed grain and a surrounding zone with a bigger grain size, was modelled as an uniform region of processed material.

Based on analysis of the related experiments datum , the principal compressive mechanical performance under static load were expounded perfectly, and a number of mechanical parameters such as compressive strength, compressive elastic modulus and compressive constitutive relations were obtained.
The whole loading process can be recorded by the computer connected to electronic universal testing machine, the maximum compressive capacity of bamboo plywood in each axis has been listed as Table 1(grain direction for z axis, horizontal grain direction for y axis, thickness direction for the x axis, simulated coordinate systems are referred to Fig4).
From the table 2, it can be seen compressive strength for M1 can be up to 70 MPa in grain direction,25 MPa in horizontal grain direction,31 MPa in thickness direction;and for M2 there are 53 MPa, 47 MPa, 32 MPa instead.
The compressive strength in grain direction of northeast larch is about 51 MPa, which is similar to M2 and lower than M1[3].
The deflections of bamboo plywood has been listed as Table 3.With the formula referred to code 2007, compressive elastic modulus in grain direction can be calculated and listed as Table4.

Two hundred grains were measured per sample.
Grain size as a function of annealing temperature (a).
Areas containing a mixed grain size distribution (b).
For annealing above 850ºC grain growth took place.
Acknowledgments   The authors thank FAPEMIG, TEC process number APQ-3318-5.07/07 and CNPq, process number 476377/2007-2, for the financial support to carry out this research.

The structure of these alloys in the annealed condition is represented by α-phase and a large number of β-phase.
The number of β-phase at this area is 74%.
The number of β-phase in the weld metal amounts is up to 60.3%.
Metal HAZ β-up equiaxed grains.
"Effect of yttrium addition on grain growth of α, β and α+ β titanium alloys."

Further doping results in increase the number of Co4+ ions and the system gets divided into two phases with different properties.
The identification of phases was based on the JCPDS base card numbers 04-007-6831 (LaCoO3), 00-028-1229 (La0.9Sr0.1CoO3) and 04-007-8983 (La0.8Sr0.2CoO3).
Surface observations confirmed the results of the X-Ray analysis that the grain size of Sr-doped layers was smaller than the grain size of the undoped LaCoO3.
The doping of LaCoO3 by Sr resulted in the decreasing of grains size and the change of the morphology of the grains from polygons to triangle.
This work was financially supported by the National Science Center through project number: UMO-2013/09/B/ST8/01681.

Model of austenite grain growth at slab heating: , (2) where d is the final average grain size, is initial average grain size;is activation energy; [m], is empirical coefficients.
The shorter the interstage cooling (INC), the smaller austenite grain will be received before the finish rolling, ceteris paribus and the ferrite grain after the final treatment.
Grain growth model is described by equation (Eq. 2).
The purpose of the finishing rolling phase is to obtain the deformed austenite grains deformation bands in the grains, which raises the effective surface area of austenite and allows to obtain a large amount nucleation of ferrite grains location to get substantially crushed grain ferrite.
Calculations using the model (15) showed that for steel with a yield strength of at least 510 MPa is necessary to have ferrite grain size not more than 7 um (11 grain size), and the increment value Dsppt not less than 110 MPa. reduction increment Dsppt by reducing the vanadium content in the steel can be compensated ferrite grain refinement to 6-5 um (12 grain size).

The DCT volume captured in the vicinity of the crack comprises of more than 5000 grains (including twinned grains).
Some of the grains have been numbered to highlight the correlation between EBSD map and DCT volume The closure occurred because the secondary crack (imaged) was shielded by the primary crack from the 80% maximum tensile stress imposed during the scan.
Features are closely linked to the grain structure; however, the grain boundaries obtained from the DCT volume do not always exactly match the observed sharp changes in crack plane.
Acknowledgments The author would like to acknowledge the EPSRC, Grant number EP/H022309/1, EP/H500375/1 and Rolls-Royce plc. under the TSB project 'Siloet' TP NUMBER: AB266C/4 for funding and the Prof Lindsay Greer of the Department of Materials Science and Metallurgy, University of Cambridge for provision of facilities.
The role of grain boundaries on fatigue crack initiation – An energy approach.

@gmail.com, cspv_61@mail.ru Keywords: structuring, diffusion coefficients, components, grain-size distribution, electron-probe test, homogenization Abstract.
It has been revealed that Fe, Cr and Ni heterodiffusion coefficients are influenced not only by their own concentration, but also by structuring kinetics and the number and distribution of the graphite in charge.
The given paper proves that the powder-component grain-size distribution alloys should be selected on the basis of relative values of the heterodiffusion coefficients.
Introduction A distinctive feature of diffusion processes during sintering and homogenizing annealing of multicomponent charges products is the implementation of a number of mass transfer mechanisms [1 – 3].
In the Ni powder layer the austenitic structure has been formed on the grain borders of which a diffusive porosity has been observed.