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The desire to understand the nature of these grain boundary phases has resulted in a number of investigations on sialon glass formation and properties which have shown that these glasses possess higher refractoriness, elastic modulus, viscosity and hardness compared to the corresponding alumino-silicate glasses.
Introduction Grain Boundary Glasses in Sialon Ceramics Sialon ceramics are recognised as ceramics for high temperature structural applications [1- 4].
Sialon Glass Formation and Properties The desire to understand the nature of these grain boundary phases has resulted in a number of investigations on sialon glass formation and properties [7-13].
Crystallization of Sialon Glasses - Glass to Glass-ceramic Transformation Heat treatments to crystallize the grain boundary glasses in sialons can lead to improvements in the thermomechanical properties of these ceramics [1] and this has led to more detailed work on the crystallization behaviour and microstructure [11, 19-21] of bulk glasses similar to those present at sialon grain boundaries.

Samples were easily collected because the creek in LANJIAN mine are small, slow and fine-grained.
Fig.1 Sampling spot Handling and analysis of sample Samples were loaded into plastic closure pocket after collection, numbered and recorded in detail.
The samples were numbered after processing and sent to the laboratory for analysis.
The content of heavy metals in fine-grained samples is significantly higher than that in coarse-grained samples.
The content of heavy metals in fine-grained samples is significantly higher than that of coarse-grained samples.

Typical measurements and results of the calculation of roundness (particles before abrasion) grain no.
Sidrap before abrasion, sample A a. white in colour and transparent grains; b. 80% sub-angular and 20% sub-rounded; c. 60% high and 40% low sphericities 0.25–0.49 5.
Sidrap before abrasion, sample B a. white in colour and transparent grains; b. 80% sub-angular and 20% sub-rounded; c. 65% high and 35% low sphericities 0.25–0.49 6.
Ottawa, standard sand a. white in colour and transparent grains; b. 70% sub-rounded, 20% rounded, and 10% well-rounded; c. 90% high and 10% low sphericities 0.35–1.00 From the second laboratory, the shape of the particle was reported qualitatively for two samples of Sidrap sand before abrasion, and Ottawa one (Table 4, rows 4–6).
In terms of grain color and transparency, Sidrap sand before abrasion had similar properties with Ottawa standard sand, i.e. white-transparent (see also Fig. 4a and 4b.).

When 0.6 wt.% Al is added into the BHSS, some pearlites take place and precipitate in the matrix near grain boundary, as shown in Fig.1b.
Moreover, the ferrite appears in the interior of the grains.
Instead, the matrix principally consists of ferrite and a little pearlite at the grain boundary (as shown in Fig.1d).
From Fig.6, it can be seen that the very small secondary borocarbides are dispersively precipitated at the inner of martensite grains.
Obviously, a number of dislocations is found in the matrix and they are tangled together and form high-density dislocations, which may be attributed to the Al addition dissolved into the matrix.

Moreover, coarse grain structure was found at higher spindle speed due to higher amount of heat, fine grain structure was at lower spindle speed.
Sigma phase which is a chromium-rich phase found within grain boundaries due to higher spindle speed.
It leads to refined grain structures within the stir zone with deformation.
On the other hand, higher welding speed creates a number of defects in the weld zone such as tunnel defect, poor welding with less strength.
On contrary higher welding speed is responsible for number of defects in weld zone.

The picture shows that after milling for 2 hours the powder has been significantly decreased in size and the grain size becomes 500-600nm except a few large granules.
During ball milling, reaction takes place between the reactive particles (for example, fine grains and grains with many defects).
Professor Lu L pointed out that the large number of defects caused by mechanical alloying can lower the activation energy, thus promoted the diffusion course of mechanical alloying process.
The duplicate contribution of ball milling is to decrease grain in size and to activate the solid reactants; but proper treatment at the appropriate temperature can promote the formation of TiC and Fe. 3) The XRD, SEM and EPMA results of the annealed powder indicate that the initial materials (synthesized ilmenite and graphite) can convert into Fe-TiC composite powders after milling for different time under 150V and subsequent annealing.
The morphology and elemental distribution of the annealed powder show that the grains are fully-grown after annealing treatment and can maintain a smaller size, but are prone to coagulate due to sintering. 4) After the pretreatment with mechanical activation, the apparent activation energy of reductive reaction will decrease with the extension of milling time distinctly.

Metal Substrate Material Choose and Welding Fusion Analysis In order to get high strength of the cutter tooth, the use of metal substrate materials for 45Mn, this material with manganese of carbon in low alloy steel conditioning, manganese steel can reduce the critical point, increase its quench-hardening ability; Refining pearlite grain size, interstitial and iron to form, so as to improve the strength and hardness of the steel; Also with vulcanization close, so as to reduce the hot steel brittle1.
Produce the melting of metal matrix part of grain growth has "nail pierced" effect, so the grain for smaller, form a narrower fine-grain area 6.
And Fe-Cr element can the azeotropic distillation of the infinite, Cr, Ni, Mn, Fe between has the very big solubility, therefore contains high Cr, Ni filling liquefaction of metal and matrix grain boundaries fusion metal material 45Mn tightly together, to avoid the intermediate sandwich produce liquefaction crack 7.
Table 4 Fusion Surfacing Hardness And Erosion Wear Test Data Sample Numbers Hardness/HRC after-grinding weightlessness/g relative wear resistance/ε Multilayer composite materials 21.0 0.6459 7.83% 3.2.2.

Fusion lines on both sides of the organization have undergone significant changes close to the fusion line β causing coarse columnar grain formation, because of the quick speed time.
Conducting an internal β-crystal phase transition β → α, turns to on-proliferation causing formation of shear hcp α′ phase and β grain boundaries are left behind.
Fig. 4 (c) The weld metal is in the line of fusion and the nucleation of grains of semi-molten core is created back on the direction of the weld.
Center cooling growth is affected by temperature. α-β phase transition process is hindered to shear the formation of α′ marten site. form β grain interior and boundaries begin to form needle-like α′ film from within the organization. α′-intertwined to form a large region-wide basket organization.
The needle-like martensite woven basket organization caused a large number of phase boundaries, strengthening the weld.

Recycled ceramic sand has rough surface and a number of cracks caused by shattering process.
While, it is better for grain shape to be spherical particle.
Moreover, it is well documented that the content of powder with grain size less than 0.075mm increases with the decrease of aggregate fineness modulus.
Meanwhile, the problems of ultra fine sand are too fine in grain size and bad grading.
While the natural ultra fine sand grain size distribution is inequality and usual contain mud.

The conversion of oxide to nano-size state leads to additional decrease of the number of JT ions.
The effect is caused by the increase of grains surface where symmetry of JT ions environment is essentially lower than the octahedral one.
As a result the JT ions concentration decreases on the value about wheresgrain, Vgrain and Rgrain are the surface area, the volume and the radius of grain, D is the thickness of the surface monolayer [2].
Dependence of temperature tc and entropy Sc of transition, drops of order parameters yc, qc upon mean size of grain (L = -0.1, L1 = 0.1, D = 0.5 nm).
It can be seen that with the increase of nonstoichiometry or decrease of grain size essential reduction of all parameters under considerations takes place.