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In the case of microstructurally short cracks, disorientation of the grains and non-homogeneity of the stress field close to the grain boundaries provide the reason for the different behavior.
The micrographs were subsequently analysed and the dependence of crack length on the number of cycles was obtained.

Experimental Procedure The alloy Al-7Si-0.3Mg (A356, chemical composition given in Table 1) in combination with a small amount of the grain refiner AlTi5B1 and metallurgical sodium modification was cast in a so-called "French die", as shown in Fig. 1a.
As shown in Fig. 4a, the number of cycles to fracture is in general higher for specimens heat treated at high temperature (540°C and 545°C, 1 and 2h) than for those heat treated at 500°C (8h).
Ongoing fatigue crack propagation into eutectic regions, which intersect the same activated {111} slip band within the same grain, is slowed down by the barrier effect of the Si particles which have to be passed (Fig. 5a).

Meanwhile, the main problem that limits the application of a low-melting sealing glass in a number of cases is its high coefficient of linear thermal expansion.
On the other hand, low-temperature treatment is likely to lead to an incomplete physical interaction of the eucryptite grains with the melt due to its high viscosity, which prevents the formation of the transition layers on the surface of the eucryptite glassceramic grains.

So, it can make full use of the characteristics of nano-particles and effectively inhibit nanometer grain growing up by adding nanometer ceramic particles to cast-penetrated layer.
Choosing CO2 sodium silicate sand, numbering the prefabricated layers after fire drying.
That can further optimize the microstructure of cast-penetrated layer, promote grain refinement, and make carbide evenly distributed in the form of granular, rods, and layered structure.

Introduction Nanocrystalline (NC) and ultrafine-grained (UFG) materials have been the subject of considerable research interest for about two decades now [1].
During each pressing, the cross-section of the sample remains unchanged and consequently this technique can be repeated a great number of times, resulting in the accumulation of large strains through the alloy.
Many ultrafine-grained Al alloys have been produced by the ECAP technique, and mechanical properties of the ECAPed materials have been reported [4-6].

Until now, the investigated alloys are ongoing research to resolve, the investigation was carried out to employ rapid quenching by melt spinning to produce Mn–Ni–In Heusler alloys by JLSánchez Llamazares et al [9], and the ribbons of Ni-Mn-In Heusler alloys grain preferential texture.
According to the Hume-Rothery theory [10], electron concentration is from 7.88 to 8.04 because of the valence electron number of Gd , and the crystal structure stability is decreased so that the martensite transformation temperature rised.
Being the new small peaks, the grain boundary second phase increased significantly that can be known the increase of Gd content.It is shown that the martensite is Monoclinic structure with the 10M and the austenite is face-centered cubic structure.The enhance of the magnetic properties is obviously shown because of the addition of Gd , however, the increase in coercivity is not proportional with the Gd content.

Results and Discussion In the past few years there has been a growing interest in a new class of materials called nanocrystalline, nanophase, nanostructured, or ultrafine-grained materials [8-10], consisting of nanoscale particles or grains (1-100 nm).
By varying the current under these low energy milling conditions, both the length of nanorods, and the number of joined nanorods was observed to increase with increasing current.

Lime rock reduced stone of continuous grain composition of Weifang, have a grade 5mm-20mm, sediment percentage 0.39%, air dry, native rock strength 55.6±8.9Mpa, apparent density ρoa=2.669g/cm3 , stacking density =1560 Kg/m3 .
The grain composition of yellow river sand meets the necessity of JGJ53-92.
On the other hand, by observing the SEM microstructure of sample interface, a number of crystal dense C-S-H gel grow or cover with fly ash particles surface, which reduces gap ration, enhances interface bond effect, and then improves mechanical properties of fly ash concrete.

Therefore, deformation compatibility between grains is improved.
Meanwhile, the diffusion creep and variation of grain orientations have also an impact on the decrease of flow stress.
The contour numbers indicate the efficiency of power dissipation in percent and the shaded areas represent unstable regions.

Materials (1) Cement :42.5 ordinary portland cement ; (2) Fly ash: Two ash; (3) River sand: The medium sand, fineness modulus of 2.27, water content is 0.67%; (4) Desalination of sea sand: Through test determination, chloride ion content is 0.01%, grain composition in the two district, fineness modulus of 2.62, water content is 3.51%; (5) Not washed sea sand: Through test determination, chloride ion content is 0.05%, grain composition in the two district, fineness modulus of 2.51, water content is 5.59%. 2.
The concrete mortar number classification in table1.