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The small pores can be caused by the combustion of the organic substance used as a pore-forming agent, and the large pores may result from the accumulation of particles with a large grain size range.
Herein, the shape of the ZnO clusters was irregular, and the number of ZnO grains was reduced because of the less porous substrates.
Therefore, the number of adsorbed dye molecules is degraded and the photocatalytic activity is enhanced because the placement of catalysts in the porous material enhances the adsorption capacity [47].
Nikazar, technology, An investigation into the simultaneous influence of withdrawal speed and number of coated layers on photocatalytic activity of ZnO thin films, J.
Chen, Technology, Method for determining crystal grain size by x‐ray diffraction, Cryst.

This criterion has been approved, and critical values have been obtained using a number of industrial projects from different areas of application.
This assumption was also made taking into account a number of industrial cases considered in comparison with simulation results (some of which are presented further in the chapter dedicated to industrial validation of the model).
Dependence of mean stress on plastic strain for points at the highlighted area Industrial Validation of the Model To verify whether the proposed criterion of underfilling formation allows for a qualitative assessment of designed tools, a number of industrial cases with a wide range of defect propagation have been analyzed (Fig. 8).
Effects of abnormal grain growth at longitudinal weld on the aging behavior and mechanical properties of 2196 AlCuLi alloy profile.
Microstructure analysis of aluminum extrusion: grain size distribution in AA6060, AA6082 and AA7075 alloys.

Ceramic composites morphology and grain morphology of fractured sample surfaces were observed by scanning electron microscopy (Oxford model LEO 4401).
The main characteristic features are low-porosity, in agreement with the results obtained for apparent density determined by Archimedes method, where all ceramic composites show densities higher than 92% of the theoretical density (considered the limit for avoiding oxygen gas permeation for using as sensors for measuring oxygen activity in molten steels) and grains with uniform shape and similar average size.
The specimens with x = 0.2 and 0.8 show fracture surface similar to the x = 0.5 specimen, an evidence that the zirconia-yttria content added to the zirconia-magnesia does not produce changes in the morphology as well as in the average grain size.
The numbers stand for the logarithm of the frequency (Hz) of the applied signal. 0 20 40 60 80 100 120 140 0 10 20 30 40 50 60 70 3 4 5 6 7 1 3 4 5 7 1 2 34 5 6 7 1 3 4 5 6 7 1 2 34 5 7 (a) pO2 = 1 ppm pO2 = 89 ppm pO2 = 170 ppm pO2 = 331 ppm pO2 = 850 ppm -Z ´´ (kΩΩΩΩcm) Z´ (kΩΩΩΩcm) 0 200 400 600 800 1000 1200 1400 0 100 200 300 400 500 600 700 2 3 567 1 2 3 4567 1 2 3 4567 1 3 4567 1 34567 (b) 0 10 20 30 40 50 60 0 10 20 30 5 6 7 4 5 6 7 4 5 6 7 4 5 6 7 3 4 5 6 7 * * pO2 = 1 ppm pO2 = 97 ppm pO2 = 165 ppm pO2 = 318 ppm pO2 = 755 ppm -Z ´´ (kΩΩΩΩcm) Z´ (kΩΩΩΩcm) 0 200 400 600 800 0 100 200 300 400 3 5 6 7 1 2 3 456 7 1 2 3 4567 1 2 3 567 1 2 3567 0 10 20 30 40 50 60 0 10 20 30 5 6 7 5 6 7 4 5 6 7 5 6 7 5 6 7 (c) * * pO2 = 1 ppm pO2 = 89 ppm pO2 = 170 ppm pO2 = 331 ppm pO2 = 850 ppm

The broad interest in nanostructures has spurred development of a number of techniques for creating metallic nanoparticles.
The average grain size of the Al nanoparticles was estimated from the half maximum width and the peak position of an XRD line broadened according the Scherrer formula.
Fig.1 XRD patterns of the Al nanopowders From the full width at half maximum, the grain size for the sample can be calculated from half widths of the major diffraction peak (111) according to Scherrer formula:, where d is the grain size; K=0.89 is the Scherrer constant related to the shape and index (hkl) of the crystals; λ is the wavelength of the X-ray (Cu Kα, 1.54056 Å,); θ is the diffraction angle; and B is the corrected full width at half maximum (in radian).

An increasing diffusion coefficient with increasing oxygen content was reported in Pd alloys, in which oxygen atoms fills trapping sites, which are a consequence of the high density of grain boundaries or dislocations [9,10].
The Nb9Ta alloys studied here are polycrystalline with small grains and contain a large number of grain boundaries, which can form trapping sites for oxygen atoms and consequently increase the oxygen diffusion coefficient.

No obviously lamellar structure of the grain and severe agglomerates were existed in the powders synthesized without NaCl as shown in Fig. 2(a).
With the addition of NaCl, large numbers of typical laminate structure particles without obvious agglomerate can be seen in Fig. 2(b).
Besides, EDS analysis indicated that Ti:Si:C atomic ratio of the crystal grain is close to 3:1:2, which is in accordance with Ti3SiC2 formula.
The crystal grains (Ti3SiC2) were separated by the molten melt (NaCl).

Due to different lamellar directions, when lamellaes within a grain were laid at a relatively large angle from the tensile component axis, the main crack propagated through the interfaces by shear or tearing, and the fracture surface was flat.
While the lamellaes within a grain were nearly parallel to the tensile component axis, the main crack propagated translamellae through linkage with the two types of microcracks, interfacial and translamellar microcracks, and the fracture surface was rough.
When the specimen is subject fatigue stress for 50 cycles, several micro-cracks are produced on the grain boundaries when the stress is 278.52MPa, and the surface damage changes little when the stress is 1989.44MPa (see fig 4d and fig 5b).
These cracks are linked by large number of micro-cracks, which appear accompanied with the low-cycle fatigue tests.

Macroscopic tensor of the defect density which has a meaning of an additional (structural) strain can be calculated by the averaging of s over an elementary volume: , (2) where is the number of defects per unit volume.
From a physical point of view this corresponds to an increase of the dislocation density in grains and grain boundaries and to the grain disorientation and intensive energy storage.

Introduction Aluminum alloys have been typically strengthened by precipitation hardening, strain hardening or ultrafine-grained hardening, but concurrent strengthening by the combination of those hardenings is expected for fabricating new metallic materials with more excellent mechanical properties [1].
This improvement in strength was due to the transgranular precipitation of the refined δ’-Al3Li phase within sub-micrometer-scale grains, and therefore it was considered that spinodal decomposition can favorably avoid heterogeneous nucleation of coasened precipitates at dislocations and/or grain boundaries even in such a severely-deformed specimen.
Here, is Avogadro’s number and , the lattice constant of the matrix, is expressed as where and are lattice constants of pure Al and Zn with fcc structure.

While RSP is acclaimed as a technique to create novel alloying compositions, a number of studies has been undertaken to explore and understand the microstructural effects in heat-resistant RS Al-TMs alloys produced at exceptionally high cooling rates (see [2] and references therein).
The RS Al has a grain size of between 4.0 and 9.0 which is decreased in Al-0.8 Cr alloy up to 2.7-6.0.
The AFM analysis indicates that RBS profiling concerns up to 103 grains in the foil surface because it was performed over the section area of a He+ ion beam 1mm in diameter.
Meanwhile, this work showed some concerns regarding the identification of peaks C and E and unclear role of secondary phases precipitates and grain boundaries which are potential H traps in Al alloys.