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A comparison between the XRD patterns of the composites revealed that the number of peaks of the ferroelectric phase and the intensity of the BT peaks increase with increasing content of BT in the composites.
The average grain size of the samples decreased with the increase of BT content.
It was found that the composites with a fine grain size provided more grain boundaries in comparison with the ferrites, which helped to provide more defects as a possible source for magnetism[12].
The dielectric structure is supposed to be composed of two layers: the first layer is ferrite grains of fairly well conducting materials that are separated by the second thin layer (grain boundaries) of relatively poorly conducting substances.
The grain boundaries were found to be more effective at low frequencies, whereas the ferrite grains are more effective at higher frequencies[15,16].

The volume fraction of new grains was defined as a fraction of grains entirely delimited of only HABs.
After ε ~2, new grains are observed both within grain interiors and on initial boundaries.
Recrystallized grains acquire elongated shape at ε~12.
Number of passes Dislocation density, ×1013 1 0.6 2 1.4 4 1.7 8 2.3 12 1.4 Effect of strain on the population of HABs and average misorientation (θav) of deformation-induced boundaries are summarized in Fig. 5a.
The volume fraction of new grains increases rapidly up to 8.

In Fig 1 (b) that shows the coarse grained region, the size of grain is coarser, the boundary of grain is clear, the internal of grain is bainitic lath, during lath, precipitating some directional carbides that are upper bainitic structure with less ductility and toughness.
In Fig 1 (c), the fine grain zone is mainly polygonal ferrite, and a little of precipitated carbides can be observed.
(a) weld seam zone (b) coarse grained region (c) fine grained region and coarse grained region (d) incomplete recrystallization zone Fig1 The microstructure of experimental BS700MC steel weld joint Fig.2 shows the microhardness distribution of experimental BS700MC steel weld join.
For heat affected zone, the upper bainitic structure of coarse grained region has a less ductility and toughness, the polygonal ferrite of fine grained region and incomplete recrystallization zone is more helpful for the extention of crack than fine acicular ferrite.
Adopting the WH80-G welding wire to weld，the weld seam structure of BS700MC steel’s joint is mainly acicular ferrite with well obdurability, in addition, the structure has very little bainite and proeutectoid ferrite; coarse grained region is upper bainite structure, the fine grain zone and incomplete recrystallization zone are polygonal ferrite.

Change of a Crack Propagation Rate in Fine-Grained Cement-Based Composites due to Partial Replacement of Aggregate by Ceramic Waste SEITL Stanislav1,a*, MIARKA Petr1,b, KLUSÁK Jan1,c, DOMSKI Jacek2,d, KATZER Jacek2,e, ŠIMONOVÁ Hana3,f and KERŠNER Zbyněk3,g 1Institute of Physics of Materials, Academy of Science of the Czech Republic, Žižkova 22, 602 00 Brno, Czech Republic 2Koszalin University of Technology, Faculty of Civil Engineering Environmental and Geodetic Sciences, ul. 
The aim of the contribution is to introduce the pilot study of the crack propagation rate in various type of fine-grained cement-based composite with different amount of natural aggregate replaced by ceramic waste aggregate.
The relationship is known as the Paris law: dadN = CDKm, (2) where C and m are material constants, N is number of cycles.
Materials To evaluate the mechanical properties of fine-grained cement-based composites with ceramic waste aggregate, test specimens were made in various moulds appropriate for the test plan.
As the level of bulk density decreases with the presence of ceramics, the fine-grained cement-based composite with ceramic waste aggregate become promising environmentally oriented building material.

The number of samples and recipes are shown in Table 1.
Meanwhile, the excess glycerol will enter into the outer crystalline regions of PVA, destroying the PVA crystalline regularity, and forming a small area of regular short-range gathering region in the outer layer of PVA grains, which decreases the integrity of PVA grains and makes grains become smaller, resulting in the obvious decrease of its melting point
It has almost no hydrogen bonding interactions within or between PVA molecules, but forms a large number of hydrogen bonds with glycerol.
Meanwhile, the excess glycerol will enter into the outer crystalline regions of PVA, destroying the PVA crystalline regularity, and forming a small area of regular short-range gathering region in the outer layer of PVA grains, which decreases the integrity of PVA grains and makes grains become smaller, resulting in the obvious decrease of its melting point
It shows that glycerol does not change the crystalline form of PVA, but destroys the crystallization of PVA by the molecules, resulting in decreasing the regularity and crystallinity of PVA grains, and increasing the proportion of amorphous regions

And this could result in the constitutional undercooling and the reduction of diffusion rate of atoms, subsequently the number of nuclei is increased and the growth of grains is restricted.
On the other hand, the enrichment of solute atoms leads to the formation of Al-RE phases, which mainly distribute in the grain boundary area, thus the grain growth is further inhibited.
In conclusion, addition of RE brings certain effect on grain refinement.
Moreover, as shown in Fig. 1(A), considerable Al-La phases, which occupy a large area of grain boundary would also coarsen the grain size of the alloy containing La, determined by linear-intercept method.
The secondary phases at grain boundary.

In the experimental measurements there have been used real particles, respectively small grain beans.
Materials and equipment In the experimental determinations there have been used real particles which form are differs from the ideal shape; respectively small grain beans particles (particles with an elongated shape) [1].
Particle type Shape approximation Characteristics Dimensions [mm] Spheroid Ф Mass [g] Length Width Thickness Small grain bean L>l≈g 13.40 8.30 7.40 0.699359 0.53 Experimental determinations were performed on a laboratory bench having oscillating flat sieves (Fig. 1) with multiple adjustment possibilities of the inclination of the block site, of the speed crank mechanism.
In order to get a final tri-dimensional trajectory, the equipments were placed on two perpendicular flat surfaces, aiming to follow the motion of the particle on flat surfaces (Fig. 3): XOY – camera video number 1 and XOZ – camera video number 2.
Experimental results Upon completion of the experimental measurements and data processing obtained there could be determined, for a solid particle number, behaviour parameters on the oscillating surface, namely: - average values of the projections on the axes OX, OY and OZ of the instant total distance travelled by the particle; Fig. 5.

The better recrystallization resistance may be related to the Al3(ErxZr1-x) precipitates, which can pin on dislocations and sub-grain boundaries.
Adding small quantities of scandium to Al alloys can refine the grain size and significantly improve the mechanical properties of aluminum alloys[7-8].
After a two-stage homogenization, Fig. 2c and d show that a large number of fine and dispersed precipitations were precipitated, the small precipitation is mainly composed of Al, Mg and Mn.
After a two-stage homogenization we can see from Fig. 3 b and c, there are a large number of precipitates, the precipitation phase exhibits two kinds of forms, one is the linear distribution, and another one is the dispersion distribution.
Addition of 0.2 wt.% Er shows no obvious grain refinement, but could refine the dendritic structure.

These features can enhance continuous nucleation, crystal separation and crystal survival, giving rise to a significant grain refinement.
All these conditions can fulfill the role of increasing the number of nucleation sites on or near the barrel wall, promote the separation on the barrel wall of crystals, leading to an enhanced effect of wall mechanisms.
Thus chemical grain refining can be used in conjunction with LSPSF process to further enhance heterogeneous nucleation, as shown in Fig. 2.
The grains flow with liquid during pouring filling the base part of the cup-shaped component, and there is not much flow near the bottom part, thus the primary grains are largely unchanged, which are nearly the same as that of before deformation as shown in Fig. 1.
For bush section, two types of grains can be found: some tiny grains between larger particles can be seen and this does not seem to derive directly from the semi-solid slurry produced by LSPSF.

The WC powder (Baildonit, Poland) had the mean grain size ~ 3 µm.
The grains of constituent phases were intensively mixed (and milled) for 4 hours.
The number of samples was 50 for each material.
Such agglomerated grains play a role of critical defects.
Grains of the metallic phase, due to their plasticity, can relax tensile stresses on the crack tip and even big grains and agglomerates don't cause excessive stress concentration.