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The number/size of microvoid/cavity, the fraction of cavity area varied with the hold time.
Under the creep-fatigue interaction, most engineering materials suffer metallurgical degradation, which causes grain weakening as well as grain boundary cavitation [1].
CN f =⋅ αγ (1) where γ is the SDA and Nf is the corresponding number of cycle to failure. α and C are the regression parameters to be determined by the regression analysis.

Although, over the last few decades, an increasing number of studies have been conducted to investigate the effects of residual stress on dimension stability of high-precision components, considerable effort is still required to provide useful guide for understanding the relationships between residual stress and dimension stability in high strength steels and to be able to design solutions to the high-precision components.
Type Ⅰ, long range stresses that equilibrate over macroscopic dimensions (the scale of the structure); Type Ⅱ, equilibrate over a number of grain dimensions (grain scale) and Type Ⅲ, over atomic dimensions and balance within a grain (atomic scale, dislocations and point defects).
Also, the pre-normalizing or quenching and tempering can refine the crystal grain of the original structure by which to obtain uniform microstructure to reduce the distortion of the component.

Zn-Al-Cu type alloys are characterized by a number of advantageous properties, which may include e.g.: low melting point, high strength and hardness, low density, low coefficient of friction [1,2].
This leads to formation of a much larger number of grain boundaries.
Within the grain boundaries atomic cores are arranged in a disordered fashion, which causes an increase of free energy.
Therefore, it is much easier to remove from the grain boundary atom than from itself grain.

A Hitachi H-600 TEM was applied to observe the morphology of samples and estimate the grain size operating at 100 kV.
The average grain size was calcaluted from the broadening of the (101) XRD peak of anatase according to Scherer formula.
As the radii of Ti4+, V 5+, Mn4+, and Zn 2+ for coordination number 6 are 74.5 pm, 68 pm, 97 pm, and 88 pm, it is easy for V 5+ ion, the radii of which is lowest and close to that of Ti4+, cooperate with the matrix of the TiO2 nanoparticles without causing much crystalline distortion, so vanadium is substituted for titanium in the matrix.
The transmission election micrographs demonstrates that the average grain size of the doped TiO2 is about 30-50 nm(showed in Fig. 2), which is well matched by that calculated according to the XRD spectra.
As the radii of Ti4+, V 5+, Mn4+, and Zn 2+ for coordination number 6 are 74.5 pm, 68 pm, 97 pm, and 88 pm , it is easy for V 5+ ion , the radii of which is lowest and close to that of Ti4+, cooperate with the matrix of the TiO2 nanoparticles without causing much crystalline distortion, so vanadium is substituted for titanium in the matrix.

Carbides are arranged at grain boundaries as well as inside grains.
In the internal zone of the bottom skull, almost 30% of the analyzed carbides is characterized by shape factor ranging between 0.2 and 0.4 (Fig. 7) and the number of precipitations with shape factor ranging between 0 and 0.2 is several times lower.
In the middle zone, the number of carbides with shape factor close to 1.0 is increasing.
It is characterized by microstructure, which is most similar to the ingot microstructure comprised of TiC carbide precipitations evenly distributed in the lamellar matrix of α and β phases, both at grain boundaries and inside grains.

The testing program included following experiments: Experiment A: Evaluation of the penetration depth of the hydrophobic impregnation (according to EN 1504-2 and EN 14630) [1], [2] Experiment B: Effect of hydrophobic impregnation on water absorption rate and resistance to alkali (according to EN 13580) [3] Experiment C: Effect of hydrophobic impregnation on the drying rate coefficient of test specimens (according to EN 13579) [4] Experiment D: Effect of hydrophobic impregnation on loss of mass of hydrophobic impregnated concrete after freeze-thaw salt stress (according to EN 13581) [5] Manufacturing of test specimens The test specimens were made from two types of concrete (see Tab. 1) with variant water-cement ratio and given maximum aggregate grain size according to the requirements of the standard EN 1766 [6].
Component Specification Experiments A and D Experiments B and C [kg/m3] [kg/m3] Cement CEM I 42.5 R 275 375 Water Ordinary water 192 168 Water – cement ratio - 0.7 0.45 Siliceous aggregate Coarse (grain size 8-16) 660 625 Siliceous aggregate Medium (grain size 4-8) 380 350 Siliceous aggregate Fine (grain size 0-4) 880 840 Admixture polycarboxylate-based superplasticizer 1.1 3.75 Air entraining admixture Microporan 0.33 0.45 Evaluation of Test Results Experiment A: Evaluation of the penetration depth of the hydrophobic impregnation The experiment was based on test method described in EN 1504-2 [1].
With an increasing number of cycles, the difference between the degradation of impregnated (see Fig. 5) and non-impregnated (see Fig. 6) specimens was also evident.
Fig. 7 Relation of average mass change of specimens and number of freeze – thaw cycles Conclusions The experiments proved that both substances (lithium water glass and NANOSYS CON02) have positive effect on the durability of concrete, which is evidenced by significant differences in results of impregnated and non-impregnated test specimens.

This paper reviews recent results on a number of internal precipitation processes which cannot be described with the Wagner theory.
The quantitative success of Eq (3) has been demonstrated for a number of systems [2].
A distinctive feature of cellular carbide precipitation is the formation of a grain boundary at the reaction front.
In order to accommodate both the preferred precipitate growth direction and the energetically favoured orientation relationship, the austenite matrix grain must be appropriately oriented, whereas the parent grain will generally not be so aligned.
For this reason, the austenite undergoes reorientation via diffusion along the high angle grain boundary at the reaction front.

The weld metal can be solidified rapidly due to the better coefficient of thermal conductivity, good heat dissipation of magnesium alloy, besides, cooling effect of the plate can also promote this process, and thus the grain was refined.
Among them, Cu, Mg, Cu2Mg and Mg2Cu have strong diffraction peaks, which indicate that the lap joint of AZ31B/Cu TIG welding consists a large number of α-Cu, α-Mg, Cu2Mg, Mg2Cu and small amount of MgO, CuO components.
Compared with the base metal, there are some intermetallic compounds such as Mg2Cu, Cu2Mg in the weld metal, meanwhile the undercooling in solidification of the metal bath is large which resulting in smaller size of the weld metal grain, and therefore exhibits high hardness.
Softening phenomenon of base metals at the heat affected zone is related to its grain coarsening.
(2) The lap joint of AZ31B/Cu TIG welding consists a large number of α-Cu, α-Mg, Cu2Mg, Mg2Cu and small amount of MgO, CuO components

Despite the huge number of studies concerning TiN films, the investigation of their structural defects remains an open problem [2].
For sub-stoichiometric the lattice parameter increases, and reached its maximum around the stoichiometric composition as a result of a reduction of number of nitrogen vacancies.
Polycrystalline TiN films typically have small grain size, and hence large grain boundary areas.
Accommodation of excess N in grain boundaries was also proposed to occur in films with extremely high nitrogen concentration, N/Ti > 1.2 [12,13] as it is the case in our samples.
Beside excess nitrogen, our films were deposited at low temperature, high deposition rate (~ 0.7 nm/s) and zero bias; three parameters which are known to be factors for creating finer and more distorted grain structure with numerous point defects and voids [14].

It indicates that the grains with different orientations were well developed, and the grain size almost range from 300 μm to 1mm.
To avoid the overlapping of the crystal lattice sites in the following STEM observation, the grain O was chosen as the appropriate area and was extracted by the FIB procedure.
Fig. 3: (a) SEM image and (b) EBSD orientation imaging maps of the sample Fig. 4(a) shows an atomic-resolution Z-contrast HAADF-STEM image of the (Cu, Au, Ni)6Sn5 thin film which was cut from grain O as shown in Fig. 3(b).
It is well known that the contrast is approximately proportional to the atomic number Z2 in a HAADF-STEM image [12].
Therefore, the brigher and darker positions correspond to Sn and Cu columns viewed from [21(_)1(_)0], because the atomic numbers of Sn and Cu are 50 and 29, respectively.