Search results

Experimental Related studies [2, 3, 4] have shown that adding element Nb can serve as a stable phase NbC to improve the strength and hardness of material, can be also used as grain refiner to inhibit TiC particles growth.
This is due to the (Nb, Ti) C solid solution formed by adding Nb (of high metal point 2468 ºC) to TiC, which can improve the plasticity, toughness and inhibit grain growth, as studies [5,6] reported.
While (b) and (c) show that the number of cracks and other defects were significantly reduced, the organization was relatively dense and the material uniformity was well improved.

On both sides of the interface is not smooth, there are a number of AlN grains embedded into the Ti layer (Fig.5 (b)).
When the crack propagation goes through the metal layer, the flexuous pattern will be occurred, and the crack expands along the grain boundary.

It denotes the greater number of the fragments of concrete substrate left on the sample of resin mortar.
At the same time, while analysing the obtained photographs of resin mortar microstructure, it may be noticed the uniform covering of aggregate grains with the resin binder.
Analysis of photographs of resin mortar microstructure taken on mortar fragments broken-off from the concrete substrate indicated the uniform covering of aggregate grains with resin binder.

A number of factors must be taken into account in choosing a suitable dispersant for a particular system, such as the particle surface, solvent, and other additives in the slurry [7].
As shown in Fig.3 (a), the Si3N4 grains are rod-like and homogenous.
Compared with Fig. 3 (a), the the arrangement of the Si3N4 grains with solid loading of 35 vol.% is more compact (Fig. 3 (b)).

We found the workplaces wich are probable more expoused to noise as a professional insult: · Graining machines – workplace occupied by maitenance electrician and engine attendant which is taken care of the graining machines.
It is estimated that the number of people in Europe with hearing difficulties is more than the population of France [6]

The requests for them are very strict, including the mechanical properties, grain fineness and supersonic inspecting.
Fig.2 Distribution of inclusions ×100 Fig.3 Analysis of energy spectrum for inclusions With the rapid development of metallurgy, especially the application of vacuum technology, the number of inclusions in steel ingots has reduced to a very low level and the quality of steel ingot has improved greatly.
Some cracks may be longer than 10mm and recovering will take a very long time, which may yield coarse and mixed grains impacting quality of forgings.

Despite the application potential of nanocrystalline diamond compact, there are still a number of technological difficulties to overcome.
During the HPHT process similar to one used in the commercial manufacture of synthetic diamond, one of the important phenomena observed of nanocrystalline diamond is abnormal grain growth.
The widening of the peaks lies on ultra fine grains of nanocrystalline diamond.

From the previous research [6-8], it can be known that the as-grown CMCs have a typical turbostratic structure in which there are a large number of defects and grain-boundaries.
That is to say interaction of these defects and grain-boundaries with phnons is far beyond that of phonon-phonon.

The procedure of region merging is to find and merge the regions with the best homogeneity in adjacent areas, which requires defining the homogeneity criterion in region merging. 1) Spectral and shape homogeneity criterion Spectral homogeneity criterion: if the variance and area of two adjacent regions are: ,,,, the variance and area after merging are and , the suffix i represents band number, so the spectral homogeneity criterion can be represented as: (5) Where, represents the weight of band i and must be normalized between 0 and 1.
Put spectral and shape together, we can get: (6) Where, and represent the color and shape of difference measurement criterion respectively, represents the weight of color difference measurement criterion in comprehensive criterion. 2) Spectral and grain homogeneity criterion Where, (x, y) is defined as the position of pixel in the image, c= (xc, yc) and c is the feature value of (x, y).
A new vector can be made based on cpi: (7) f can be defined as the sum of all the vectors in the window, that is , local The procedure of region merging based on homogeneity criterion. 1) Given parameters of region merging: shape weight ws, firmness weight wc, merging scale h, grain scale H; 2) Determine merging criterion, if the scale of the result is smaller than the given scale, then we merge them, otherwise we do not merge them; 3) Select the initial objects for region merging randomly; 4) Decide whether the neighborhood object meets the conditions of merging according to the local homogeneity criterion, if it does meet, then the neighborhood object and the initial object will be merged; Otherwise, the initial object will be marked as processed, and the neighborhood object becomes the new initial object; 5) Use the same method until all the objects of the image object layer are processed.

Top surface of both samples, not influenced by the cutting process, was subsequently ground using diamond grinding discs (400, 800, 1200, 2000 grains per square inch) to reveal a smooth planar area with dimensions sufficient for the nanoindentation and in the last step polished using aluminium-oxide suspension (Al2O3) with grain size 0.05 µm to achieve minimal surface roughness.
Number of indents varied in dependence on size of the polished sample surface reaching approx. 20 indents in each indentation area.