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It is evident that the stronger ACB synthetic diamonds provide the maximal number of the cutting edges on the working surface of the grinding wheels.
The grain size of the diamond wheels has a significant influence on the forming of the roughness of the surface, since with increase of the dimension of the synthetic diamonds the micro-profile of the cutting surface of the wheel changes because of the reduction of the number of the diamond grains per unit working surface of the wheel.
With increase of the grinding wheel speed from 18 m/sec to 32 m/sec (vw = 25 m/sec; Sах = 10 m/min; Str =1.5 mm/stroke and t = 0.03), the parameter Ra decreases from 0.32 µm to 0.2 µm, which is associated with the increase of the number of the cuts by the diamond grains per unit time, and also with the decrease of the thickness of the cut that is performed by the individual grain, i.e., because of the specimens surface "sparking-out" effect.
The weakening of the bonds between the neighboring surface grains of the nitride ceramic leads to brittle fracture of the surface with the subsequent mechanical action from the active grains.
It was established that the specific number of the craters, the grooves, and the cracks on the surface of the specimens that are ground by the diamond wheel depends on the characteristic of the wheel and the grinding regime -and intensification of the grinding regime leads to increase of the number of these defects.

Increasing the solid-solution temperature to 1060°C would cause parts of the NbC to dissolve, thus a large number of the thin sheet-shaped NbC would appear in the solid-solution and aging specimen.
Fig. 1(a) shows that massive precipitations are distributed within the grain boundary, and they display irregular shapes with the average size of 20 ± 1 μm.
Fig. 1(a) also shows a large number of needle precipitations (δ phases (Ni3Nb)) around the irregular Laves phase.
The irregular Laves and needle of δ phases obviously appeared within the grain boundary, as shown in Figs. 2(a) and 2(b).
It is reasonable to suggest that the main controlling factor of yield stress is precipitations rather than the grain size for alloy 718.

Microstructure evolution and tensile properties were studied in a bainitic pipeline steel grade by performing a number of physical simulations on samples machined out of an industrially produced transfer bar.
During the rough rolling the austenite grain size is refined due to repeated cycles of work hardening and the recrystallization process.
The austenite status at this stage - regarding the prior austenite grain size (PAGS) and precipitation - simulates the condition of austenite after the roughing process.
On the other hand, a value of 60 s for tV was enough to attain the saturation point for large prior austenite grains deformed at high temperature (Fig. 5b and 5e).
Summary Microstructure evolution and tensile properties were studied in a pipeline steel grade API-X80 by performing a number of physical simulations on samples machined out of an industrially produced transfer bar.

The studied sample contained large grains with grain size of approx. 0.5 to 3 mm.
A large number of indentation tests was carried out on the sample with a loading rate of 0.2 mN/s.
The average indentation hardness (5.0±0.4) GPa was similar as to the first grain, however the average elastic modulus (75±2) GPa was substantially different from the average value obtained in the first grain.
(Grain 2).
The average hardness (5.0±0.4) GPa in the second studied grain was almost the same as in case of the first grain.

Spherical grains can be obtained by several semisolid processes in aluminium alloys.
As the dislocation density increases, there will be more grains for recrystallisation.
Thus, grain structure will be more refined [2].
Spherical grains of 7075 (a) treated at 575oC for 35 min (b) treated at 600oC for 20 min Fig 2 shows the SEM image of the spherical grains of 2024.
Comparison of the elongation at fracture results for 2024 and 7075 alloys Fatigue tests were applied after PH process to several numbers test bars in both quenching mediums (Quenching in RT Water / RTW-Q and Quenching in Boiling Water [80°C] / BW-Q after SHT).

A small number of laser shots and a low temperature of substrates (series 1) probably slowed or stopped the processes of diffusion and coalescence of the already grown grains, which caused the situation that substrates were not uniformly covered with BN.
Registered grains have similar, small sizes (Fig. 1).
The morphology and phase maps of boron nitride coatings An increase in the number of laser shots, the energy of laser and the power of the RF discharge generator (series 4) cause that the substrate is completely coated by boron nitride; moreover, a larger variety of the size and shape of grains can be observed, as a number of quite large grains with an elongated shape have appeared.
On the surface of large grains and among them, a significant amount of small grains can be observed.
Such variation in conditions resulted in the noticeable growth of the grain size.

Most of these effects are related to the nanometer-scaled grain size.
Carbon will pin dislocations and grain boundaries, slowing down the dynamic recovery process.
This is in contrast to the ductility which is limited by the number of inclusions.
The number of inclusions and the purity content are correlated.
An increasing amount of impurities leads to a higher number of non-metallic inclusions, restricting the intrinsic ductility.

The Schulz back reflection method is used to measure three incomplete pole figures numbered {111}, {200} and {220}.
Figure 3 indicate that the shape of the recrystallized grains is irregular.
With increase the holding time, the grains grows up gradually.
In the initial stage of the annealing, the grains have a faster growth rate while there are no significant changes in the grain size with the time passing.
Therefore, the sample display a weaker recrysatlllization texture and finer recrystallized grains.

The grain size number was determined from the microphotograph taken at 100X magnification and analysis using the comparison method as per ASTM E112-10.
The grain size corresponds to ASTM grain size No; as per ASTM E-112.
The grains of pearlite show no elongated grains.
The grain size corresponds to ASTM grain size No; as per ASTM E-112.
The grains of pearlite show no elongated grain.

The method provides the greatest number of information when testing the stents' surface and it is well applicable for the analysis of surface alterations caused by different specific tests, e.g. fatigue test.
The most frequent surface failures of the coronary stents before expansion: a) small holes, b) inclusions, c) slip lines, d) failures caused by the mechanical finishing After balloon expansion the number of surface failures is increased, in strut bends, when the material has had bigger use, grains slip, slip lines and grain boundaries occur.
The reason could be that the stress was rather concentrated at grain boundaries compared to the inner part, and the grains were better deformed there [4].
Presence of slip lines and grain boundaries mainly occurred in the strut bends.
Some grains were also observed on the surface.