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SEM micrograph shows the mullite grains in the shape of short rod with length of 20 um when sintered at 1200 oC for 2 h and the grains grown up to acicular with length of more than 50 um when the treating time under 1200oC achieved to 4 h.
To promote the growth of the grains, the sintering temperature is set as 1200 oC with a heating rate of 5oC/min and the hold time is set as 2 h and 4 h, respectively.
A large number of mullite crystalline in short rod shape with size of 20 um can be observed in Fig.4 (a).
This means the mullite grains have been fully developed under long time heat treatment.

The amplitude of the resistance change depends on the material, number of cracks, size of cracks and Eigen frequencies of the sample excited by ultrasonic wave.
When grains are smaller, the contacts are weakly non-linear or even ohmic only [1].
Each set of varistors was prepared with different size of grains.
Varistors from the first set (varistors for 660V) were consisted of the tiny grains.
The second set (varistors for 280V) was prepared with larger grains which means good quality.

The average grain size of the test pieces after the heat treatment was about 250µm.
Orientation of individual grains was measured by EBSP in the SEM.
Silver particles were visible not only on the slip lines, but also on the grain boundaries near the notch in a T6-tempered alloy as shown in Fig.6.
This implies that hydrogen is transported to the grain boundary utilizing the slip lines with the aid of mobile dislocation.
There might be a correlation between the grain boundary misorientation and the accumulation of hydrogen at the grain boundary, as well as the slip mode in grain interiors. 100μm a b c a b c 5μm 5μm 5μm Fig. 4 HMT images in the longitudinal direction near the final fracture point (a), (b) and (c).Summary Hydrogen emission behavior during fatigue deformation of an Al-Mg-Si alloy was investigated using hydrogen microprint technique.

The experimental steel are complete recrystallization, and 100% ferritic structure, and grain sizes about 10.0 to 11.0 grade.
With coiling temperature increases, when the same cold reduction ratio, the grains coarsening somewhat.
Under different coiling temperature, with the cold reduction ratio increase, the ferrite grain change more small, and the grains are equiaxed.
This is because in the cold rolling process, the grain was deformed, along with the cold reduction ratio increase, the number of the deformed grain increaseed, during annealing nucleation position increased, deformation by reply and recrystallization, grain annexed grew up, so restricted -phase recrystallization grains comparison after small homogeneous.
With the increase of coiling temperature and ensure that performance, the ferrite grain grow up, and helpful for {111} structural development.

The inclusion of metal oxides can improve the grain boundaries, suppressing grain boundary corrosion.
Besides, the average grain size of alloy in Fig. 1(c) is less than that of alloys in Fig. 1(a) and Fig. 1(b).
From the SEM photograph in Fig. 2(a), the grain boundary segregation is seriously and the catenoid precipitates distribute in the grain boundary.
In addition, the number of segregation in Fig. 2(c) is sharply less than that in Fig. 2(a).
The reason may be attributed to the grain refinement and the augment of the grain boundary proportion. 0 1 2 Fig.3.

Superposition of the action from successive grains requires assumptions about the shape of "active" cutting grits and estimation of active grit density.
To practically use Eq. 1, one has to perform a large number of, time-consuming, grinding tests to estimate R0 and n, and the dependence of heq on other grinding variables.
This approach reduces the number of required experiments, by eliminating the need for testing different workpiece materials, wheel speeds, and equivalent wheel diameters.
Grinding tests are performed using wheel grades ranging from soft (H) to very hard (R), and from coarse-grained (#36) to fine-grained (#120).
Coolant fluid flushes workpiece debris and fractured abrasive grains; thus, keeps the wheel sharper.

The surface morphology observed by scanning electron microscopy (SEM) indicated that the grains of the Al-based composites sintered at 550 ºC were uniform and compact, which were in agreement with the properties of high density and tribological properties.
Recently, a number of researches on AMCs prepared by different methods were reported.
The enhanced relative density of the samples of ball milling is mainly due to the grain size refinement.
When the sintering temperature increased, the density of sintered compact was increased gradually, the microstructure changed from bimodal-grained to coarse-grained structure.
The yield stress of composites increased with the increase of sintering temperature up to 550 ºC and decreased because of grain coarsening with further increasing the temperatures.

Polyethylene terephthalate (PET, grains) depolymerizations were catalyzed by SO42- /γ-Al2O3 superacids in pure water under microwave irradiation with a reaction time of 150min, a temperature of 190°C and a pressure of 200psi.
Pure PET resin was obtained in the form of fiber-grade commercial chips supplied by LiaoYang Petrol Chemical Fiber Corp (LiaoYang City, PRC), the mass average molecular weight (Mw) of PET was 38905, the number average molecular weight (Mn) was 25703 and the viscosity-average molecular weight was 18197.
A typical sample in the experiment contained w1 of PET grain, solidsuper acid catalyst and 20 mL of distilled water, which were put in the reaction vessel without stirring.
In all experiments, there were 2g of PET grain and 20mL of distilled water in the reaction vesse, and the conditions of reaction time 150min, temperature 190°C and pressure 200psi were the same.
High concentration of SO42- would jam the metal oxide holes, reduce number of surface active centers and even cause side-effect of Al2O3[5], so the catalysts soaked in 3.5mol·L-1 H2SO4 was also less effective.

Based on the results, it is clear that certain samples picked up varying amounts of interstitial impurities during processing and as a consequence a significant number of micro-cracks were observed in lamellar type microstructures.
An intercept method was used to measure a minimum of 100 grains and 200 colonies per sample.
In addition to these microstructural features, a small number of pores are also present.
However, there is some variation in the grain and colony size due to an orientation effect.
The value of mean linear intercept length (estimated grain size) measured on a longitudinal cross-section suggests that the grains present here are elongated compared to those in the transverse direction.

Substructure conditions of grains in rolled material form an extremely wide spectrum and vary by passing from texture maxima to texture minima, where residual deformation effects are most significant.
Introduction When starting from concepts of texture formation, it can be anticipated that grains of the deformed polycrystal differ in substructure conditions, determined by initial and final orientations, active plastic deformation mechanisms, affiliation of the grain to that or another part of the texture maximum.
In order to make certain of this supposition by means of direct systematic measurements, the X-ray method was developed, enabling to obtain separately data on grains with any possible orientations.
Usage of GPFs by the study of residual elastic microstrains allowed to reveal a number of new facts concerning their distribution in textured materials.
Distribution of Residual Elastic Microstrains GPF 2�hkl describes the anisotropic elastic deformation �hkl(�,�) of grains along axes due to action of residual microstresses.