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Compared to Al-Ti-B grain refiner, TiC in Al-Ti-C grain refiner, the heterogeneous nucleation core, has less aggregation tendency than TiB2.
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It has been shown that the creep resistance depends on a number of factors, including the shape of the component phases, the strength difference between the phases, and the stability of the beta phase.
In fine grained alloys, twins in either phase are unlikely, as it has been shown that twins only form in large grained alloys during creep deformation at ambient temperature [13].
In Ti alloys creep strain at ambient temperature is reduced as grain size is decreased [14].
The interaction of the alpha and beta phases of Ti-8.1wt%V, could result in the activation of additional deformation mechanisms from those seen in the single phase materials with similar grain sizes.
This research is being funded by the National Science Foundation under award number DMR-0102320.

The results show that the structure of YAG ceramic is loose with spherical grain size of 0.2-0.3μm.
It can be seen from Fig.4, the crystal grain arrangement of the surface of YAG is loose, but the grains composed of continuous irregular long strip particles are very uniform and smooth, without other structure, size of the grain is about 0.2-0.3 μm.
According to Table 2, the main mineral composition of dots 1, 2 at bright area in Fig.6 is crystalline Y3Al5O12 with higher average atomic number, while the dots 3 at dark area is unreacted Al2O3 and Y2O3.
Fig.6 XRD pattern of YAG ceramic sample Conclusions ①The YAG ceramic is prepared by co-precipitation method, it is white with density of 2.42g/cm3 and a little of shrinkage , and its surface quality is better. ②Shown from the microstructure and morphology of YAG ceramic, it is loose and microporous, with grain size of 0.2-0.3μm. ③The main mineral phase of YAG ceramic is composed of polycrystalline Al5Y3O12, have a relative perfect crystallinity and small amount of impurities.

When the concentration of sodium citrate was 40g/L, the substrate was completely covered by Ni-W-P plating, the surface was composed of uniform crystalline grains, and had no obvious defects and presented amorphous.
The substrate was completely covered by Ni-W-P plating, the surface was composed of crystalline grains and had no obvious defects.
Relative to b in the coating, the surface of a was composed of uniform crystalline grains, the size was small and had no obvious defects, the above results were because of containing more phosphorus in plating a and it is easy to phosphorus segregated at the grain boundaries.
Table 1 the bond strength for different concentration of sodium citrate Serial number concentration（g/L） Bending test File test 1 20 Flaking Peeling 2 30 Flaking Peeling 3 40 Without flaking No peeling 4 50 Without flaking No peeling 5 60 Without flaking No peeling 6 70 Partially flaking Peeling 7 80 Partially flaking Peeling Conclusion The plating rate has been increased firstly, and then decreased with the increment of sodium citrate concentration in the range of 20-80g/L, the maximum plating velocity was 9.14μm/h.
When the concentration of sodium citrate was 40g/L, the substrate was completely covered with Ni-W-P plating, the surface was composed of uniform crystalline grains and had no obvious defects and presented amorphous.

Table 1 K40UF Carbide chemical composition and main mechanical properties WC Co Cr3C2+VC Grain Density Rockwell Tensile Toughness Thermal size (WC) hardness strength conductivity 89.5% 10% 0.5% 0.6 14.5 91.7 2500 3600 75 [µm] [g/cm3] [HRA] [J/m2] [N/m2] [W/m.
Fig.2 ELID grinding measurement results However, because of effects of the grinding equipment, grinding force and grinding heat ,and so on, the processed surface is left with a large number of very fine grinding marks, and accompanied by changes in the microstructure, thermal stress layer, residual stress layer and the grinding cracks[5].
So obtaining the nano-scale ultra-precision surface is difficult The following is that using mechanical grinding and polishing techniques studied the effects of abrasive type, grain size, polishing liquid composition, polishing time on the carbide surface roughness.
As polishing progressing, the alumina grains crushed between the cemented carbide and polishing disk are not easy to maintain shape, broken faster, and the capability of removing material is greatly reduced.
Fig.4 Measurement with polishing fluid B Fig.5 Measurement with polishing fluid A Impact of Abrasive Grain.

Tab. 1 The relationship between the two description forms of FCC metals twinning variants Number twinning plane and twinning direction rotation angle\rotation axis T1 () T2 () T3 () T4 () Application Fig. 3(a) and (b) display separately the grain misorientation graph of GH690 and GH145 superalloy specimens cut from extruded pipes by the same extruding technology, in which the extruding velocity was 40mm/s, the pipe was heated to 1200℃ before being extruded, the extruding die was heated to 350℃, and the extruding ratio was 5.
In Fig. 3, there exist twinning bands within some grains ten of them are chosen for analysis and numbered from 1 to 10, and the letter M nearby every number represent the matrix of every twinning band.
Based on the analysis above, it can be concluded that there are large number of 60º\<111> twins formed in the areas as shown in Fig. 3.
Tab. 4 Results of analysis on the twinning variants of the GH690 superalloy specimen Grain No.
Tab. 5 Results of analysis on the twinning variants of the GH145 superalloy specimen Grain No.

The grain sizes lied in the range of 1-130 µm.
These crystal grains were encapsulated by the glass phase, providing good compactness and high strength.
Although the crystal grains and distribution looked similar to those in Fig.3 and Fig.4, the spherical grains were identified as zirconium silicate in contrast to zirconium oxide in Figures 3 and 4 (according to Figures 1 and 2).
The grain sizes lied in the range of 5-120 µm.
Small spherical grains with the sizes of approximately 4 µm attached on several big crystal grains while a large number of plate-like grains, i.e. silicon carbide, were regarded as the causes of reduced instant temperature gradient in the sample, which would subsequently reduce the internal stress, thus improving the volumetric stability during thermal shock. [7, 13] Fig.5 SEM morphology of the fractured surface of sample C5 fired at 1280℃ Fig.6 SEM morphology of the sample C5 fired at 1280℃ after 30 times testing of thermal shock resistance（room temperature~800℃, air-cooled） Physical properties.

The length of grain in main growing direction is approximately 1um, the grains are refined.
The structure is essentially unchanged and there still be a large number of primary α crystal at 320°C.
With heating time, the number and the shape of silicon particles precipitated from the matrix were changing gradually.
For 60-100min solution, the silicon particles precipitated grow slightly but still less than 3µm while grain roundness increases significantly (Fig. 4c and 4d).
Solution for 250min, the Si particles precipitated coarsen and grain boundaries cusped seriously.

Hence to have statistics on many grains, a manual counting has been preferred.
The observation of continuous nucleation is important information for the transformation mechanism; The β phase grains are not distributed very homogeneously from one α grain to another and frequently β grain nucleation occurs at a grain boundary.
The β grains grow without crossing the grain boundary.
The experimentally observed number of grains per unit surface is reasonably described as linear with time (Ns(t)=b*t): b is the slope of the surface nucleation curves.
It is worth noting that very good agreement is found for the lamellar morphology with a limited number of adjustable parameters.

According to Lanska et al. [5] a lower valence electron number per atom favours the formation of the 5M martensite (cf.
In this region also a grain selection takes place.
In the second zone columnar grains can be seen.
Above this cone in zone 3 all the grains are globular.
It is possible to apply a large number of training cycles without any harm to the samples.