Search results

If the grain size is a, then the number of grains is 1/a.
So the strain per grain boundary is (α∆TLa).l-2.
Combining the CSC with the equation derived for the strain per grain boundary Campbell [2] modified and expressed it by the following: [(α∆TLa).xl-2 ][ tV/tR ].

However, detailed microstructural analysis via scanning and transmission electron microscopy of the material upon performance under severe service conditions (750 ºC for 200 and 4000 hours) revealed an unexpected degradation of the matrix grains.
A large number of ceramic materials have been identified that can be doped with aliovalent cations to create extrinsic oxygen vacancies required for proton conduction.
Results - Microstructure Evolution The sintered Y-doped BaCeO3 discs showed a homogeneous microstructure with equiaxed matrix grains, 1-2 µm in diameter.
The SEM image shown in Fig. 3 shows a very characteristic feature of the Y-doped BaCeO3 after service in the fuel cell assembly; step-like defects within the matrix grains.
Note the characteristic step-like feature within the matrix grain.

Even though a large number of papers are already published on the microwave dielectric properties of MCT ceramics, effect of different particle size on the sintering behavior and microwave dielectric properties of 95MCT ceramics have not been reported.
The grain sizes of powders were observed by scanning electron microscopy (SEM, HITACHI S-4800).
The curves also show that there is no weight change since the end of the decomposition reaction after 457 ˚C, and the exothermic peak around 667 ˚C associates with the crystallization and growing of grains that can be confirmed by XRD and SEM.
Compared with (d), larger grains are observed in (a) and (b), which suggests that the grain growth is improved by the high surface energy of nanoparticles.

The coarse grain turn up, simultaneously the plasticity corrosion resistance descend to a low level.
Experimental materials and methods Cu-base combustion welding rod, with diameter of 15mm, length 160mm is made according to Fig.1 including Plug, Thimble, Grain, Igniter and Casing.
The grain is connected and installed onto the casing through the plug when welding, holding the bottom of the casing.
Ignition of welding rod is achieved with igniting the igniter and then the grain start to combust.
Copper and copper alloy’s manual SHS welding produce a number of Al2O3 in the combustion synthesis reaction.

Agar plays an important role in boosting BC production which is related to the increased fermentation liquor viscosity, BC particle dispersity and free cell number. 4.2 Effects of additives on structures Adding hemicellulose, xanthan, lignin sulfonate, tetraethoxysilane, sodium alginate, multilayer carbon nanotubes and polysaccharides into the original culture media influence the output, form (macroscopic form, fiber ribbon intertwining and width), microstructure (crystal structure or degree of polymerization) and physiochemical performance (viscosity, mechanical performance, thermal performance) of BC.
The microscopic analysis showed that there was hydrogen bonding between BC and sodium alginate, and BC grains were tinily sized with low degrees of crystallinity.
Profitably recyclable Carbon-source type natural substrates, such as fruit juices (coconut water, watermelon juice), starch hydrolyzate, soybean whey, sugar cane molasses, leaching liquor of distiller's grains, glutamic acid hydrolyzate, soybean enzymatic hydrolyzate and industrial methanol wastewater, are able to effectively lower the fermentation cost while maintaining the BC output. 5.1 Natural products 5.1.1 Fruits In the 1840s, the Philippine and Indonesian people have begun to produce and sell a health food "Nata" that mainly comprised BC.
Shen et al. [26] reported that Acetobacter xylinum produced 2.17 g/L cellulose in the leaching liquor of distiller's grains of Chinese liquor together with rice hulls and 2% saccharose at pH 5.0 and 30°C for 15 days, which were higher than those using the distiller's grains of beer or Chinese liquor alone. 6.

First, the number of the pores reduced and the diameter of the pores decreased.
Third, as the graphite concentration increase, some ball-shaped grains or particles appeared on the coating surface.
Some of the grains were trapped in the pores, which reduced the roughness of the surface.
But when more graphite were added in electrolyte (such as 8 g/l), many ball-shaped grains were assembled on the surface which can be seen from Fig. 3(d).
For coating obtained in electrolyte with 8g/l graphite, the ball-shaped grains assembled on the surface made the surface roughness increase a little.

Further cooling initiates the formation of the austenite phase nucleating at the ferrite grain boundaries.
Microstructure of welded deposits consist of characteristic dendritic grains oriented almost perpendicular to the fusion line.
The matrix is ferrite with a number of acicular austenitic precipitates.
Lower heat input gave more fine austenite grains.
The microstructure consists of lamellar austenite precipitates that surround equiaxial, large ferrite grains.

However it should be borne in mind that the number of full size coupons is small
The as-cast microstructure shown in Figure 3a exhibits a very fine grained microstructure with a divorced eutectic.
After the solution Treatment (T4) ß-Mg17Al12 precipitates were dissolved in the matrix but significant amount of grain growth is observed.
The grain growth and precipitates after T6 treatment might also be the reason for the reduced yield strength and low ductility.
This can be attributed to the observed grain growth.

Introduction Nanocrystalline materials with grain size of less than 100 nm are being developed due to their excellent and superior mechanical, physical and chemical properties.
Compared to conventional coarse grained materials, these materials possess lower elastic moduli, higher tensile strength and hardness, increased ductility, fatigue resistance and super plastic behavior under certain conditions [2-3].
Smaller granules size of CoNiFe is due to the presence of greater number of grain boundaries [13].
This is because the existences of grain boundaries that prevent dislocation motion and subsequently result in harder material [13].

Delta ferrite, rich in Cr and Mo, formed during the welding of austenitic stainless steels is required up to a limit of about 4-5 ferrite number (FN) in order to avoid hot cracking or micro fissuring of the weld metal [1,2].
It is well known that the stir zone consists of fine and equaled grains produced due to dynamic recrystallysation [11].
Increasing the rotational speed to more than 1000 rpm has significant effect on the wear of the tool .Finally it seems that the 1000 rpm rotational speed is acceptable for fabricating SiC/316L composite and Fig. 8 shows the perfect grain refinement and also SiC particles in microstructure of the FSPed sample at a rotational speed of 1000 rpm and traverse speed of 14 mm/min in 500x zoom.
The microstructures were evaluated by observing the grain size at different rotational and traverse speeds of the tool and the dispersion of the SiC.
(4) The FSP with the SiC obviously increases the microhardness of the substrates by the promotion of the grain refinement and SiC`s extremely high hardness.