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Introduction NiAl-based alloy have a number of attractive properties including excellent oxidation resistance, high melting temperature, high thermal conductivity and relatively low density.
In the NiAl-Cr(Mo)-Hf alloy experienced large superplastic compression both the matrix grains and Cr(Mo) grains were refined, and the microstructure was improved obviously.
The shape of the grains became irregular and disorder.
The other reports demonstrated that the superplastic deformation of NiAl-based alloy was mainly achieved by grain boundary sliding and after deformation the grain coarsening was obvious [6].
Acknowledgements This work was supported by the National Natural Science Foundation of China under grant number of 10477006.

The volume of the grains oriented in this way was approx. 20 %.
Also, the sizes of the grains are differentiated (Table 1).
Beside large grains one can see clusters of very many, very small grains.
Those small grains are approximately 10 times smaller than the large ones.
The reason of such a course of the martensitic transformation could be decreased number of structural defects during extruding at 900°C and occurring dynamical recrystallisation.

Samples dimensions and the average weights Test type b [mm] h [mm] l [mm] Wmean [kg] Four - points bending 50 60 1300 1.5561 Tensile parallel to the grain 15 26 300 0.045 Tensile perpendicular to the grain 45 180 70 0.213 Compression parallel to the grain 45 70 300 0.359 Compression perpendicular to the grain 45 90 70 0.107 Shear parallel to the grain 32 55 300 0.203 Shear perpendicular to the grain 300 55 32 0.198 Laboratory tests loading details The number of test samples was determined according to Standard ISO 3129: “Wood.
Laboratory tests information Test type s [mm/min] t [s] V [%] Number of tested specimens Special conditions Four - points bending 10 333 20 16 · Span of 1100 mm; · Distance between loads application points of 360 mm.
Failure modes, reached at fracture stresses Test type Failure mode at fracture stresses Four - points bending - the timber grain split due to tensile stresses Tensile parallel to the grain - timber chipping close to the specimen ends Tensile perpendicular to the grain - horizontal grain splitting, close to the specimen ends Compression parallel to the grain - the grain was crushed and folded at samples mid-height Compression perpendicular to the grain - the timber compacted and folded at samples mid-height Shear parallel to the grain - grain splitting along fibres direction Shear perpendicular to the grain - grain splitting along fibres direction Fig. 1.
Experimental results for tensile test: a) parallel to the grain: stress-displacement curves; b) parallel to the grain: timber specimen failure; c) perpendicular on the grain: stress-displacement curves; d) perpendicular on the grain: timber specimen failure.
Experimental results for shear test: a) parallel to the grain: stress-displacement curves; b) parallel to the grain: timber specimen failure; c) perpendicular on the grain: stress-displacement curves; d) perpendicular on the grain: timber specimen failure.

Nitrogen causes distortions in the diamond structure due to the mechanical stress and the increase in the number of defects (vacancies).
Experimental In this work, we prepared nitrogen-doped diamond films with different grain sizes.
Besides, as the N2 concentration in the gas-phase increases, the number of CN species increases.
The threshold value of nitrogen required to bring about the grain size transition is in the range from 3 to 10 sccm.
The nitrogen doping variation influences the film growth rate promoting changes in the grain sizes.

When mutual grain boundary (GB) diffusion of oxygen and aluminum occurred in wafers subjected to a steep DPO2, the oxygen and aluminum fluxes at the inflow side of the wafer were significantly smaller than those at the outflow side.
The durability of these components is generally controlled by the barrier’s performance with respect to oxygen permeation through grain boundaries (GBs) in the polycrystalline alumina scale formed on the alloy surfaces, which are exposed to a steep oxygen potential gradient (DPO2).
On the other hand, the oxygen permeability of a wafer co-doped with Lu and Hf was found to be significantly higher than that of an undoped wafer, probably because Lu-stabilized HfO2 particles formed at GBs by a reaction between the two dopants offered extremely fast diffusion paths for oxygen due to the large number of oxygen vacancies in the particles [4].
Thus, the dopants are supposed to effectively decrease the number of sites, of which oxygen and aluminum jump to their vacancies at the nearest neighbor sites.
The GB density, Sgb, was calculated by dividing half of the total grain boundary length for more than 200 alumina grains by the total grain area, as determined by image analysis of laser scanning micrographs of the wafer surfaces after the oxygen permeation tests.

As well known, nanostructured materials have demonstrated superior properties over the conventional coarse-grained counterparts such as hardness, strength, ductility and toughness [5, 6].
The microstructure type B presented columnar grain structures, as shown in Fig. 8.
The columnar grain structure type B originated from the molten parts of the agglomerated powders.
Further investigation has proved that the CSZ coatings sprayed with conventional powders only consisted of the micrometer-sized columnar grain structures.
Fig. 10 shows the effect of nanostructured and conventional CSZ coating thickness on the number of thermal shock cycles to failure of the coatings.

Grains were identified by a tolerance angle of 2° and a minimum grain size of 5 pixels.
This would indicate that the {011} and {111} grains should not deform until the {001} grains had hardened sufficiently to initiate slip in the grains of higher Taylor factor.
Initially the hard grains deform very little while imposing greater deformation on the soft grains.
For this type of plot to be representative of the bulk material a large number of grains would need to be included (>1000 grains) [cf. 28].
The small strain sample initially showed a greater incremental increase in {001} type grains, while the {011} type grains surpassed them in incremental increase in the number of excess dislocations at a true strain of 0.05.

Such tools typically have a metal body with a diamond-bearing layer consisting of diamond grains covered by metal bonding.
Upon subsequent heating to temperature not exceeding 1100oC brazing alloy melts, encompasses diamond grains and fixes them to the substrate.
The interactions of composite brazing alloys with diamond grains are currently not well researched.
Components in the brazing alloy Sn-Cu-Co-W provide its chemical interaction with a surface of diamond and wetting diamond grains.
Despite their absence the emerging from brazing alloy metal matrix solidly hold diamond grain. 2.

It is clear that the average grain size decreased with the increasing of the Ca and Zr contents.
The grain size of all samples was smaller than the sample sintered at 1400/15/700/6 condition.
It is reported that the grain size is strongly dependent on the sintering methods, and also the sintering temperature and soaking time [8] such as if T2 is too high, grain growth still occurs in the second step.
Acknowledgements This research is financially supported by Prince of Songkla University under contract number SCI560371S.
Wang, Sintering dense nanocrystalline ceramics without final-stage grain growth, Nature. 404 (2000) 168-171

The crystalline grain size of the three powders is closed to each other.
Tetragonal and cubic zirconia can be stabilized by making solid solutions with number of additives such as CaO, MgO, CeO2, Y2O3 and with other rare earth oxides.
The crystalline grain size could be calculated by Scherrer equation, as shown in formula (1)
When ammonia was used as precipitant, the crystalline grain size of the MgO-ZrO2 powder is about 30nm.
The crystalline grain size of the three samples is closed to each other.