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A great number of efforts were contributed to research the anode materials for many years.
During the alloy preparation, Ca and Sr must be controlled strictly so as to impel to produce fine grain structure of minimum segregation.
Fig.4 reveals the number of anodes changed and electrolytic deposition time with using complex alloy and Pb-Ag alloy as anode materials.
From Fig.4 can find that the number of changed anodes in using complex alloy was obviously more than using Pb-Ag alloy.
When the complex alloy anode was used, it could easily cause corrosion holes around the anode, hence increased the number of plates that need to be changed and it also had short life span.

Numbers in alloy grade describes the cobalt content, according to which alloys differ in flexural strength, density and hardness.
Alloys are divided into three groups according to their structure: fine-grained, medium-grained, coarse-grained.
In the case of increasing cobalt percentage and grain size, the toughness of alloy grows.
Medium grained and coarse-grained alloys with low cobalt content were suggested to be used for reinforcement of tools, working under conditions of shockless loads.
Acta Montanistica Slovaca Volume 22 (2017), number 2, 107-115

Distance from basic material Flowdrillových holes and heat-affected zones shows a typical single-phase microstructure of austenitic stainless net polyhedral twin austenite grain boundaries.
Grain edges were only sparsely detected during etching, showing very low carbon content and a negligible margin granular carbide settling in the heat affected zone as a result of thermal effects of thermal drilling process Flowdrill, Fig. 5.
Table 1 The measured values of hardness HV 0.5, depending on the distance from the surface of the hole Number of measurements 1 2 3 4 5 6 7 8 9 10 11 12 13 Distance [mm] 0,25 0,75 1,25 1,75 2,25 2,75 3,25 3,75 4,25 4,75 5,25 5,75 6,25 Hardness HV 0,5 305 270 255 235 230 225 215 225 215 220 215 225 220 Number of measurements 14 15 16 17 18 19 20 21 22 23 24 25 26 Distance [mm] 6,75 7,25 7,75 8,25 8,75 9,25 9,75 10,25 10,75 11,25 11,75 12,25 12,75 Hardness HV 0,5 225 220 210 220 215 210 210 215 210 215 220 215 225 Fig 6 Relation of distance from the hole surface and hardness Conclusion The results of experimental investigations, it was found that the highest hardness values ​​were measured in the vicinity of the hole surface and towards the inside of the base material hardness gradually decreases.
Flowdrill processes have caused improvement and deformation of the basic material microstructure with hardening of the austenitic grain to the depth of 3 mm around the hole surface.
The effects of heat on the microstructure are minimal and no carbide deposits appear on the rims of grains and zones formed by heat, which could conversely cause corrosion of this type of material.

Table 2 Size of the measured point Number of measured point 0 1 2 3 4 5 6 7 8 9 10 11 12 Direction of measured point （away from the weld joint center, mm） 0 2.5 -2.5 6 -7 12 -12 24 -24 36 -36 -60 -96 After welding, different processes of heat treatment were carried on the tensile specimens, see details.
Table 3 Distribution of residual stress of the measured point between welding joint Measure point (mm) Number of point Strain (e) Main stress (MPa) XI Ni ei sx y -36 10 -10 90 60 4.019655326 -8.55869 -24 8 -42 -12 91 2.449354003 -0.39846 -12 6 -10 10 30 -1.941775031 -1.33676 -7 4 -20 -60 80 23.5367943 4.425367 -2 2 -125 -195 -15 55.42547461 18.31 0 0 -7 -105 -128 75.09096228 4.522731 2.5 1 -100 -66 70 42.74805459 7.944821 6 3 -33 -78 110 25.5850957 5.684046 12 5 -24 12 76 -5.475928881 -2.62064 24 7 -20 -20 66 5.245213229 -0.34557 36 9 -30 16 50 8.228387935 -1.30154 Fig.1 Distribution of residual stress When the weldment is locally heated, inhomogeneous expansion is formed due to the existence of the inhomogeneous temperature field [5].
The grain is long in the vicinity of fusion zone, and the grey phase and dark phase are θ (Al2Cu) phase and S (CuMgAl2), respectively.
As is shown in Fig.2e, the α-Al matrix with round edges can be found and the secondary phase was precipitated along the grain boundaries.
The prorogated grains remain the same, and lots of fine secondary phase was precipitated as well as the precipitates within the grain.

Phase identification showed single phase of MgTiO3(PDF number #790831).
In all cases grain growth were detected during sintering.
Average grain sizes were 2.3µm for MZTA, 3.4 µm for MZTB, and 1.8µm for MZTC.
It showed the role of B2O3 and Bi2O3 liquid phases were to reduce sintering temperature, however they cause grain growth.
Reece, Effect of Porosity and Grain Size on the Microwave Dielectric Properties of Sintered Alumina, J.

Our samples were all prepared using argon (Ar)-ion-milling technique, which produced flat surfaces allowing the quantification of types and number of pores in two dimensions.
For example, in Fig. 2A, interparticle pores are developed between quartz (Qtz) and calcite grains with cement overgrowths.
In Fig 2C and 2D, grain-rim interparticle pores are found along the edge of particles and are possibly related to matrix separating from the particle during compaction.
They are elongated roughly parallel to bedding, except where they bend around a rigid grain.
Interparticle pores in Fig. 2E grow at the interfaces between clay and rigid grains.

After the firing, disk-shaped specimens, 16 mm in a diameter, were prepared to 0.5 mm in thickness with grinding using polishing materials containing diamond grains (Zircoshine, Shofu, Japan) (Fig. 1).
Sintering time and temperature strongly affect to the growth of grains [5, 6].
Therefore, it would be considered that the size of the grains were about the same as those of sintered by standard firing.
Acknowledgements This study was supported by JSPS KAKENHI Grant Number JP16K11629 from the Japan Society for the Promotion of Science.
Ahn, J, Kim, H, Kim, W, Kim, Effects of the sintering conditions of dental zirconia ceramics on the grain size and translucency, J.

In this work, monoclinic zirconia and dolomite nanoparticles with an average grains size of about 50nm were obtained through the high-energy ball milling process.
For the production of nanosized ceramic powder, a number of synthesis techniques are currently available [1].
The mechanical activation during the high-energy milling reduces the particle size and introduces a high concentration of defects in the material (dislocations, high-angle grain boundaries, etc.).
Consequently the necessary temperature and time for the densification of the material is reduced, thereby providing more control over the grain growth in the densified material.
Figure 3 shows a homogenous matrix of cubic zirconia with tetragonal precipitates (white grains) with a grain size of 30 nm.

The abstract of the paper began as: “The grain structure of a casting is commonly described in terms of alloy composition, cooling rate, and nucleation.
It showed that metal flowing past columnar grains causes the grains to grow in the “upstream’’ direction, and explained the result in terms of the then quite new work of Bruce Chalmers and his students on “supercooling” in dendritic growth.
We were delighted to see the columnar grains that grew in the first case pointed nicely upstream.
The casting at the bottom of the figure had its end plugged so filling occurred as in a usual casting; the result was a largely equiaxed grain structure.
Utech, Process for Making Solids and Products Thereof, Patent Number 3,464,812; issued September 2, 1969

A number of nickel-based superalloy with high stacking fault energy was undergone room and high temperature deformation.
Microstructures become more homogeneous and grain growth rate is increased.
The mean grain size after recrystallization, disregarding twinning, was about 41-45μm with increasing cobalt.
Shear bands and grain boundaries were identified as preferential nucleation sites at 1473K.
All of the samples undergo continuous recrystallization, grain size was gradually decreased with cobalt addition. 5.