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Serial number Pass reduction（mm） Actual wall thickness reduction（mm） Radial spinning force（Ton） 1 1.0 0.85 6.5 2 2.0 1.62 14 3 3.0 2.43 21 4 4.0 3.37 29 5 5.0 4.21 36 When the pass reduction was set to 5.0 mm, the spinning process was prone to overload causing the equipment to stop running.
The microstructure after annealing was recrystallized, the ferrite grains were significantly refined, and there were carbides distributed at the grain interface and inside.
Annealing and recrystallization leaded to the refinement of ferrite grains.
Compared with Fig. 3(b), the grain size was larger.
There were carbides distributed at the grain interface and inside.

Experimental procedure Homebred commercial analytically pure (99%) AIN powder with mean grain size of 4.51 μm, high purity (99.9%) Mo power with mean grain size of 3.2 μm, analytically pure CaF2 and CaCO3 are listed in Table 1 according to the designed composition.
Table 1 Chemical composition of samples studied Serial number AlN /vol % Mo /vol % CaF2 /wt% CaCO3 /wt% 1 82 18 1 0 2 82 18 2 0 3 82 18 3 0 4 82 18 0 1 5 82 18 0 2 6 7 82 80 18 20 0 1 3 0 8 80 20 0 1 Results and discussion The XRD patterns of AlN-Mo composite with hot pressed sintering is shown in Fig.1.
Except for sample No.1 (the sample with 18vol% Mo and 1wt% CaF2), the others have high sintering densities and close combinations among the crystal grains.
And CaAl2O4 and Ca3Al2O6 will form CO and volatile compounds of Ca. it is conductive to deoxidizing, cleaning grain boundaries and reducing the content of impurity phase, to further improving the AlN-Mo composite ceramics’ thermal conductivity [8-11].
(3) The thermal conductivity of composite ceramics improved by sintering additives with the increasing of sintering density of AlN-Mo composite ceramics , the decreasing of oxygen content and purifying grain boundary and other aspects.

Blade material model must include elastic-plastic deformation and fracture properties for the strain rates up to 105 - 106 s-1 [5].There are a number of material models of varying degrees of difficulty which describes the behavior of materials at high strain rates.
They are mostly different in accounted factors and number of experimental parameters to be defined [13, 14].
Samples in form of plates made of the micro-grained and nanocrystalline structure alloy were investigated.
The first group of samples is the simple sheets with micro grain size (M).
The second group of samples is made by a special deformation process of grain refinement to get uniform equiaxed nanocrystalline structure (N) with a grain size of 100-500 nm [15].

As shown in Fig. 2, with increase of the aging temperature and time, the grain sizes do not change obviously.
A large number of fibrous structures exist along the extrusion longitudinal direction.
When the aging temperature increases to 200 ˚C, the (AlFeSi) particles in size of about 1-3 μm are precipitated at the grain boundaries.
When the temperature exceeds a certain threshold, the precipitated particles are easily nucleated and grown, especially at the relatively high-energy grain boundaries and dislocations [12].
That is possibly the reason why the larger (AlFeSi) particles precipitate at grain boundaries shown in Fig. 3(f), (g) and (h).

Due to the special structure of ultrafine grain, it has the following several aspects of the effect, and thus derive special properties which traditional solid does not have.
Band theory showed that atomic number contained in ultrafine powder particles is limited and level spacing spitted.
Surface effect refers to the ratio of atomic numbers in the surface of ultrafine powder and the total number of ultrafine powder sharply increased with the decrease of the particle size.
With particle size decreasing, the surface atomic number increased rapidly, the particle's surface tension and surface energy increased too.
In mould manufacturing production, the finer grain, the bigger the specific surface area, and it is easier to mold and sinter[18].

The cost-effective manufacture of near-net shape titanium articles from sintered powders reduces the number of machining processes.
Therefore, grain growth was reduced.
The poor elongation is due to the coarse primary β-grain, as Fe is a strong β-stable element.
The low diffusivity of Mo in Ti would hinder the migration of grain boundary and this is beneficial to the microstructural refinement for Ti alloys.
Al is a α-stable element, so the enhancement of the α-phase is acceleration and shown the grain growth. 3.

Compared with that of Mg-10Y alloy, the microstructure of Mg-10Y-1.5Sm alloy has two significant features: (1) The grains of the alloy are more uniform and their average sizes are decreased to about 60μm. (2) The secondary phases are finer particles and their distributions are more uniform and dispersed.
Fig. 3 SEM image of microstructure of Mg-10Y-1.5Sm alloy Table 2 EDS analysis result of particle A and area B in Fig. 3 Element Particle A Area B wt% at% wt% at% Mg 66.32 87.98 89.27 96.94 Y 32.37 11.74 9.67 2.87 Sm 1.30 0.28 1.06 0.19 Based on the above results, the refinement effects of rare earth Sm on the grains of the alloy can be described as follows: (1) Part Sm dissolves in Mg matrix during the solidification of the alloy.
It increases the number of homogeneous nucleation, and refines the grain sizes. (2) Part Sm dissolves in Mg24Y5 phases, increases the stability and blocks the growth of Mg24Y5 phases.
In addition, during the solidification of the alloy, high melting point compound Mg24Y5 (the dissolved Sm enhances its stability) precipitates and acts as a bar to the growth of α-Mg grains, and leads to further refinement of the grain sizes.
Of course, additional strengthing mechanisms, grain refinement strengthening of Sm and dispersion strengthening of Mg24Y5 (the dissolved Sm enhances its stability) also play important roles in strengthening of the alloy.

However, applications of alumina as a structural ceramic are limited by low fracture toughness owing to its equiaxed grains.
The investigations [1-3] show that fracture toughness of alumina ceramics can be increased by adding α-Al2O3 platelets, which induce the anisotropic grain growth of equiaxed grains.
According to solution-precipitation reaction, amorphous Al2O3 particles tend to dissolve and precipitate on the surface of seeds that provide a large number of potential nucleation sites [5].
The toughening mechanism in sintered alumina is the grain-bridging mechanism.
This effect is much more effective in microstructures containing plate-like anisotropic grains than it is for equiaxed grains [9].

Required number of cycles was 200 000.
Microstructure of components “A”, “B” and “C” consists of ferritic polyhedral grains with small amount of pearlite.
Some areas with irregular grain size after recrystallization process were also observed.
Material exhibited deformed ferrite grains in the subsurface areas and areas of inner radius.
Except the component “D”, microstructure was formed by polyhedral grains (with some areas of different grain size).

It is possible that patterns are observed in isolated regions where local grain growth may have occurred.
The decrease in droplet density with increasing bias is consistent with prior published literature which reports decrease in the number of droplets at higher bias voltages in cathodic arc deposited TiAlN coatings [8].
The reduction in grain size has been confirmed by preliminary TEM studies carried out.
A tangible reduction in grain size could be observed between the TiAlN coating deposited at -100 V and the one deposited at -150 V.
Preliminary studies suggest that the bias voltage could also influence the grain size and thereby affect the above properties.