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RMS surface roughness of NCD films by HFCVD method in terms of deposition temperatures Surface roughness is closely related to the grain size, nucleation density and secondary nucleation [5, 6].
The higher deposition temperature makes a faster growth rate which resulting in a bigger grain size.
The number of particle reaching to substrate, with low speed and low energy, will drop.
The result limits the secondary nucleation of diamond films which occurs in the grain boundary of diamond films causes the roughness to decrease.
The variation of surface roughness of different deposition temperatures is believed to arise from the difference grain size, nucleation density and secondary nucleation.

The phases were identified bearing in mind that β phase is more susceptible to etching (dark grains in Fig. 3).
In coin no. 2767, β and γ are the predominant phases: γ phase precipitates at β grain boundaries.
After etching, β grains are darker, while γ phase is brighter (Fig. 5).
The α grains are clearly distinguished in OM while β (darker after etching) and γ (light grey) phases are finely distributed between the α grains (Fig. 7).
Conclusions Chinese coin composition depends hugely on a great number of factors.

Moreover, a decreased carbon content can improve resistance to intergranular corrosion, also known as grain boundary corrosion [2].            
The number of pits is much greater for the 1344-hours than for the 672-hours, and can be compared with theory, in particular the PREN index, a pitting corrosion resistance index with the relationship: PREN = Cr% +3.3Mo% +16N % (6) [14] Accordingly, for the EN 1.4306 (304L) stainless steel sheet, the PREN (Pitting Resistance Equivalent Number) index is as follows: PREN= 18.02 + 3.3*0.38 + 0 = 19.27 % (7) Fig. 5.
The uniform polygonal grains that make up the structure are typical of austenitic stainless steels.
These microstructural alterations may also be associated with differences in mechanical properties, such as the reduced tensile strength of the purple zone compared to the yellow zone, which maintains finer grains and intact grain boundaries [30].
This might be the result of diffusion towards grain boundaries or local segregation brought on by high temperatures [36].

As shown in Fig.3(c), the surface oxide grains of Sn63Pb37 solder is about 4µm in diameter, and many second-phase particles appeared on the oxide grain boundary.
In Fig.4(d), the surface oxide grain in Sn63Pb37-P solder is finer without second-phase particles on the grain boundary.
The result (table2) shows that the second-phase particles which appeares in the grain boundary of the oxide grains are iron-rich phase oxide(Fig3. c-A).
By the principle of backscattered electron imaging, the backscattered electron yield is very sensitive to the atomic number.
Therefore, the sample area on the atomic number higher is brighter because of more backscatter electronic collected [11] .

The grain size of primary Al plays an important role in the final properties of the casting.
For the grain refiner master alloy to act as an effective dopant, the physical nature (shape, size morphology or number density) of the pre-existing phases in the master alloy play a key role in the microstructural development during casting [5].
Chakraborty, Grain refinement of aluminium and its alloys by heterogeneous nucleation and alloying, Int.
Zhang, Revisiting the role of peritectics in grain refinement of Al alloys, Acta Mat. 61 (2013) 360–370
StJohn, An analysis of the relationship between grain size, solute content, and the potency and number density of nucleant particles, Metall Mater Trans A, 36A (2005), 1911-1920

Compared with Fig. 2(a) and (b), with the decrease of final rolling temperature, both of them were within the range of bainite transformation temperature and cooling rate, and their structures were more uniform, but the bainite grain size in (b) was significantly coarser than that in (a), the number of bainite decreased, and bainite changed from equiaxed in (a) to long along the rolling direction Strip.
Because other rolling process parameters were the same, the microstructure uniformity and grain size of bainite after transformation decreased.
When the spinning temperature (T2) was taken as a variable, combined with the optical microstructure in Fig. 4 and the influence of spinning temperature (T2) on microhardness in Fig. 6, the obtained microstructure was bainite, but the grain size and number of bainite were different.
With the decrease of the spinning temperature (T2), the grain size decreased.
(4) The existence of a large number of bainite in the sample directly leads to the high strength.

Alloys used for plastic working are less popular compared to those processed via casting and therefore, the number of their grades is much smaller.
The number of alloying components in cast magnesium alloys is always higher than in alloys subject to plastic working.
In the initial state after extrusion the structure of the alloy is fine-grained (Fig. 1a), and after annealing the alloys shows a tendency to grain growth (Fig. 1b).
The presence and the size of re-crystallised grains is dependent on temperature and strain rate.
Increase of strain temperature leads to size growth of recrystallized grain (Fig. 8e, g).

This proves that there really is no RAP contained in the mixture and the aggregate grains are only coated with new asphalt binder.
This is due to the fact that during the first extraction predominantly the non-aged asphalt binder dissolves, which coats the newly added aggregate grains.
During the second extraction, therefore, the aged asphalt binder is dissolved, which coats the RAP grains (aged asphalt binder is stiffer and dissolves slower).
Upon the third extraction, the remaining asphalt binder dissolves, which is closest to the surface of the aggregate grains and especially the RAP.
Various “burnt” residues of asphalt binder can remain attached to the surface of the RAP grains (the so-called black rock).

The much refined grain size in the SFed composite is due to fast cooling and solidification rates during SF and the restriction from grain growth by the embedded tiny ceramic particles.
The grain sizes of the cast and PM AZ61 composites with 0.2% or 1vol% nano-SiO2 are also included in Table 1 for comparison.
Also listed are the hardness data which are consistent with the grain size.
The BEI contrasts for Si and Mg are weak due to the small difference in atomic number.
Nearly no eutectic phase Mg17Al12 would form at grain boundaries due to the high cooling rate.

Chromium contained in the bulk tends to oxidize through oxygen diffusion apparently occurring along the grain boundaries.
Although at 1100 °C the whole specimen surface was covered with Cr2O3, such thick scale developed a large number of cracks (Fig. 3d) during testing.
Figures 4c and 5 reveal that under such conditions the core of the light-contrast grains corresponds to a Cr-rich composition.
Moreover, a detailed examination revealed that the outermost part of these light grains is composed of Cr2O3, thus suggesting that oxygen coming either from the air atmosphere or diffusing from the alumina grains is gradually reacting with Cr in the network.