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However, the average grain size of the laser remelted coating is much smaller than that of TIG remelted coatings.
There are a considerable number of techniques applied to create protective coatings, in particular, thermal spraying is an important and effective one [3-6].
In addition, the crystalline grains of the two kinds of TIG remelted coatings have obvious orientations, which indicate the direction of the maximum thermal gradient.
Compared to Fig. 2(b), the smaller grain size is obtained in Fig. 2(a), indicating that the water cooling condition accelerates the solidification process of melted materials.
This improvement obtained by laser remelting is mainly attributed to the fine grain structure with almost no defects such as pores and cracks.

The results indicated that the hardfacing layers revealed martensitic type microstructure in both controlled and uncontrolled cooling rate but their grain shapes were a little difference.
Table 1 Chemical composition of Mn steel plate [wt%] C Si Mn Ni Cr Mo Fe 1.08 0.85 13.5 0.33 2.06 0.05 balance Table 2 Chemical composition of electrodes [wt%] C Si Mn Ni Cr Mo Fe Hardfacing (DIN8555:E 6-UM-60) 0.5 0.8 1.3 7 1.3 balance Build-up (DIN8555:E 7-UM-250-KP) 0.6 0.8 16.5 13.5 balance Buffer (DIN8556:E 188MnR26) 0.11 1.2 4.2 8.5 19.2 0.7 balance Table 3 SMAW process parameters Electrode Current [A] Voltage [V] Travel speed [mm min-1] Number of layer Hardfacing (DIN8555:E 6-UM-60) 120-123 20-25 23-24 1 2 Build-up (DIN8555:E 7-UM-250-KP) 108-118 21-25 21-25 1 Buffer (DIN8556:E 188MnR26) 105-120 25-30 25-30 1 (a) (b) Fig.1.Schematic of welding layers deposition in the different atmospheric condition.
Specimens in uncontrol cooling rate welding; in air, carbide (Fig. 2 e) was precipitated and coarse grain area (Fig.2 g) was found in boundary between base and buffer layer, which are more than in the controlling cooling rate by water (Fig.2 f and g).
Fig.4 Mass loss of the welded specimens Conclusions · Carbide and coarse grain were generated on base metal by welding in un-controlling cooling rate by air

In the joint we have only crystalline grains deformation, phase transformation and aluminium diffusion.
The aluminum samples have a structure consisting of α-Al solid solution with strongly deformed grains in the rolling direction of the sheet in the base material (BM) and in nucleus (N) the welded structure has a modified appearance regarding the orientation (distortion ) and the grain size (larger and finer).
If the force is less than that required, then a number of slips between the tool tip and the workpieces to be welded occurs, due this phenomena it was been registered an excessive heating of the workpieces.

A number of tests were undertaken on quartz extracted from the sample prior to routine application protocol.
Grain size analysis and magnetic method were applied to detect the characteristics of Beijing dust fall on April 17，2006 [1]．Major element, trace element and REE were analyzed to examine geochemical character [2]. 10Be , 14 C ,and δ 13C in 12 samples preliminary results indicate the dust maybe from two different source [3].
Based on grain size analysis, electron scanning microscopy, energy spectrometry, measurements of water-soluble salts at normal temperature, macroscopic phenotype features and field investigations, The so-called "sand dust storm" in Beijing on April 16, 2006 was verified to be a dust storm and dried-up salt lakes were important source areas of dust storms in the Beijing-Tianjin region [4].
While applications of the Luminescence dating method to coarse-grained quartz can be considered well established in terms of dating later Pleistocene and Holocene aeolian sediments, key issues remain inrelation to the young age range of the technique, and applying SAR to silty sediments involves a far more difficult sample preparation to extract the quartz than for sand samples.
A number of tests were undertaken on quartz extracted from the sample prior to routine application protocol.

It was found that combined contributions of welding parameters contributes significantly to the metallurgical changes by varying fractions, morphology and grain size of metallic compounds.
These steels have a monophase microstructure consisting of austenite γ with an average grain size of 25µm including a considerable percentage of chromium and nickel.
The figure 11 illustrates the different steps to be followed to obtain average grain size; the average size (a) was calculated using Eq. (17).
a=1ni=1nLiXi Eq (17) Where n is the number of the selected lines, Li is the length of the line i [µm], Xi is the number of grains in the line i, for n = 8 → a = 23,926µm (Fig.11d).
Different steps to obtain the average grain size In order to examine the influence of automatic welding parameters on metallurgy of AISI 304L ASS welds in more detail.

A number of the specimens used for the strength tests ranged from 10 to 30.
The characteristic strength values and the Weibull moduli have been determined by a linear regression and by Maximum Likelihood Method both applied to the following y-x dependence resulting from the Weibull theory in the form axmy += ,                 − = fP y 1 1 lnln , ix σln= , 0lnσma −= , � i Pf 2 12 − = , (4) where fP is probability of failure, � is number of measured values of the strength iσ related to the i-th measurement, and an increase of the natural number i is required to correspond to an increase of a value of iσ , i.e. 1+≤ ii σσ for i = 1, …, �.
Si3N4 (SN I) exhibits moderately elongated Si3N4 grains with the aspect ratio of approximately 3.
The Si3N4 (SN II) has a bimodal grain size distribution with large grains up to 10 µm in length, and small ones, i.e. <1 µm in diameter.The SiC microstructure consists of fine submicron-sized equiaxed SiC grains with a low aspect ratio.
Additionally, all materials contain an inter-granular phase in a form of very thin grain boundary films as well as in a form of triple points.

The grain sizes were also determined.
Smaller grain size makes it easier to produce very hard and small details such as sharp edge tips [10].
Grain size and product density can be designed by regulation of sintering temperature and duration [7].
The grain size was found to vary from 0.9 to 1,4 µm with average of 1.22 µm.
The data collection rate was automatically set by the controlling program supplied by SETARAM to store the maximum number of data points.

The machining parameters, such as rotation speed, oscillation speed/number and feed speed, have direct impact on the tangential force coefficient.
The machining parameters, such as rotation speed, oscillation speed/number, and feed speed, and the lubrication parameters, such as temperature, pressure and flow rate, are set as the variables in the experiments.
The feed speed and oscillation speed/number are also set constant in each test.
Table 2 System Configuration Machine Rotation speed [r/min] Oscillation number Feed speed [μm/min] Oscillation speed [mm/min] 350 10 3 1000 Workpiece Material Diameter[mm] Machining length [mm] Premachining roughness Ra [μm] 20 MnCr 5 25 20/100 1.5-2.0 Lubrication Variation Viscosity n at 40 °C [mm²/s] paraffinic basic oil 1 2.3 paraffinic basic oil 2 12 naphthenic basic oil 1 2.9 naphthenic basic oil 2 9 The honing stone sintered with diamond grains of 15 µm, has been chosen as the abrasive tool.
As described in literature, this means a higher abrasion, amongst others due to more sharp grains [10].

These properties are strongly dependent on some distinctive structural features of foils such as thickness, grain size, grain boundaries morphology and dislocation structures [25,26].
As foil thickness decreases, the grain and cell structure progressively evolves into coarser and less organized grains, which appear relatively free of tangled dislocations in their interior.
Red arrows indicate some areas where grain boundary sliding occurred.
Seven configurations can be identified depending on the number of Cr atoms present in a single octahedron.
MgZn2 precipitates inside the grains and along grain boundaries (a).

Non-equilibrium superplastic materials such as bulk amorphous alloys and those, which show phase transformation superplasticity, essentially differ on rheological behavior from fine-grained superplastic and coarse-grained not superplastic materials.
The data on a number of superplastic bulk amorphous alloys in comparison with parameters of some nonmetallic glasses are presented in Table 1.
The more fine the grain, the higher the strain rate of superplastic deformation.
Higashi [8], consists in assumption of existence of liquid phase areas on grain boundaries or entire liquid boundaries at high temperatures as one of possible mechanisms of accommodation of grain boundary sliding.
And the third point is grain size of HSRSP materials, which is typically less than 1 µm.