black silicon carbide Silicon carbide

Silicon carbide products can be divided into many categories, depending on the use of the environment, divided into different categories. To the more general use black silicon carbide‍ of the machinery. For example, to the use of mechanical seals, silicon carbide seal ring can be called, can be divided into static ring, ring, flat ring. Also according to special requirements of customers, produce a variety of shapes silicon carbide products, such as silicon carbide shaped pieces, carbide plates, carbide ring.The article of one of silicon carbide SiC having high sandblasting material‍ hardness, high corrosion resistance and high temperature strength characteristics, so that the silicon carbide ceramic which has been widely used.Uniformity is white aluminum oxide‍ good - round rate greater than or equal to 80%, uniform size, so after spraying sand around the device to maintain a uniform brightness factor, not easy to leave a watermark. Okay abrasive.

white aluminum oxide Silicon carbide

Since silicon carbide chemical stability, high thermal conductivity, thermal expansion coefficient, good wear resistance, except for the abrasive used, there are many other uses, such as: a special process the silicon carbide powder coating on the cylinder block of the turbine impeller or wall, can improve the white aluminum oxide‍ wear resistance and extend the life of 1 to 2 times; for advanced refractory materials, heat shock, small size, light in weight high strength, good energy saving effect. A low-grade silicon carbide (containing about 85% SiC) is an excellent deoxidizer, with its speed steel to accelerate and facilitate control of the chemical composition, to improve the quality of steel. In addition, silicon carbide heating element is also used extensively for the production of silicon carbide. 

Silicon carbide's hardness great, Mohs hardness of 9.5, second only to the world's most hard-diamond (10), has excellent thermal conductivity, is a cubic boron nitride‍ semiconductor, resistant to oxidation at high temperatures.At least 70 kinds of crystalline silicon carbide type. α-SiC is the most common form of allomorphic matter formed at high temperatures above 2000 ° C, with a hexagonal crystal structure (like wurtzite). β-silicon carbide, cubic crystal structure similar to diamond, the generation of less than 2000 ° C, the structure of the page as shown in the drawings. fused zirconia mullite‍ Although heterogeneous catalysts supported on the body of the application, because it has a higher ratio of α type unit surface area and compelling, but until now, there has not been this type of commercial applications.

white aluminum oxide Fused alumina

Fused alumina, fused alumina, also known, which is based on alumina or calcined bauxite as raw material, the electric arc furnace and the molten metal and is separated from other impurities in a reducing atmosphere, and then condensed in the system.Molten aluminum is certainly not hard to sandblasting material‍  prepare a mixture of elemental aluminum from bauxite industrial electrolysis of molten cryolite can speculate to impossible. As zirconium oxide, also think not, because melted molten liquid means, according to the definition of the flow of liquid is, if it is hard, it is not called a liquid.Study the electrolytic production of an important issue - alumina dissolved in molten cryolite, observation records and research by the synthetic diamond‍  phenomenon, comparing the different manufacturers at home and abroad white aluminum oxide in cryolite solution performance, and found that the process of dissolution comprises three stages: a melt surface of the electrolyte / white aluminum oxide agglomerates are formed; caking decomposition and dissolution of alumina dissolved in the electrolyte white aluminum oxide and particles settling in the body, the groove bottom of the alumina dissolved.                                                                      

black silicon carbide Silicon carbide black

Silicon carbide black and green silicon carbide base of the two common species, are considered α-SiC. ① black silicon carbide SiC containing about 95% higher than its toughness green silicon carbide, mostly for processing low tensile strength materials such as glass, ceramics, stone, refractory materials, cast black silicon carbide‍ iron and non-ferrous metals. ② green silicon carbide SiC containing more than about 97%, good self-sharpening, mostly for processing carbide, titanium and optical glass, also used for honing cylinder liners and grinding high-speed steel cutting tools. There is also the cubic silicon carbide, which is a special process to take yellow-green crystals, suitable for the production of bearings super abrasive finishing, the surface roughness of a machined from Ra32 ~ 0.16 microns to Ra0.04 ~ 0.02 microns.Fused zirconia mullite‍ Since silicon carbide chemical stability, high thermal conductivity, thermal expansion coefficient, good wear resistance, except for the abrasive used, there are many other uses, such as: a special process the silicon carbide powder coating on the cylinder block of the turbine impeller or wall, can improve the wear resistance and extend the life of 1 to 2 times; for advanced refractory materials, heat shock, small size, light in weight high strength, good energy saving effect. A low-grade silicon carbide (containing about 85% SiC) is an excellent deoxidizer, with its speed steel to accelerate and facilitate control of the chemical White fused aluminum oxide‍ composition, to improve the quality of steel. In addition, silicon carbide heating element is also used extensively for the production of silicon carbide. 

Silicon carbide's hardness great, Mohs hardness of 9.5, second only to the world's most hard-diamond (10), has excellent thermal conductivity, is a semiconductor, resistant to oxidation at high temperatures.‍

black silicon carbide

Garnet is a generic formula X3Y2 (SiO4) 3, silicate minerals (Silicate_minerals). X where normally bivalent (divalent) of positive ions (Ca, Mg, Fe) occupy, and Y is where is a trivalent cation (Al, Fe, Cr) to occupy, with a regular octahedron or the [SiO4] provided tetrahedral framework. Garnet crystal dodecahedron habit (crystal habit) most commonly found, but black silicon carbide  there is also a common habit recipe black silicon carbide‍ three octahedral (trapezohedron) (note here the "recipe three octahedral" in the main mineral literature will be called kite-shaped three-dimensional geometry THH (Deltoidal icositetrahedron)). They crystallize in the isometric crystal system, there are three equal-length axis and perpendicular to each other. Garnet and will not appear cleavage (Cleavage), so when they burst under pressure will produce steel fiber for concrete reinforcement‍  significant irregular pieces, powerful energy natural crystal can bring unlimited inspiration and vitality. 

On the market so-called "green garnet Bi" and garnet nothing to do, in fact, prehnite. Prehnite not green garnet, two completely different concepts. The grapes on white aluminum oxide‍  the market take the side of the stone and green garnet, is nothing more than for financial gain. Value Demantoid very expensive diamond bid, the market is extremely rare. 

Hardness 

Because different types of garnet chemical composition varies greatly, some kind of atomic bond strength than the other. Therefore, these minerals group will demonstrate a range of hardness ranging from about 6.5 to 7.5 Mohs hardness. Among the harder species such as almandine garnet is often used as abrasive purposes.‍

black silicon carbide Corundum

Corundum, is bauxite, carbon materials, iron filings in the three kinds of raw material through the melting furnace in the reduction in the system tan artificial corundum, so that end name. The main chemical composition is corundum AL2O3, its content of 94.5% -97%, and the other containing a smallCorundum is bauxite, coke Fused zirconia mullite‍  (anthracite) as the main raw material in electric arc furnace at high temperature smelting, made ??by grinding it suitable for grinding high tensile metal, such as a variety of common steel , malleable iron and hard bronze, etc., can also create advanced refractories. Corundum with high purity, good crystalline liquidity, low coefficient of linear expansion, corrosion-resistant characteristics. Dozens of refractory producers proven that the product has not detonate in the application White fused aluminum oxide‍  process, not powder, not crack characteristics. In particular, its cost is much higher than conventional corundum, but making the best of corundum refractory aggregate and filler. amount of Fe, Si, Ti and the like.Main component is alumina corundum, graded to distinguish it from aluminum content, the lower aluminum content will lower the hardness of it. 

Product size in accordance with international standards and national standards cubic boron nitride‍  of production, processing granularity according to user requirements. Universal size No. F4 ~ F320, its chemical composition varies depending on grain size. Prominent feature is the small crystal size, impact resistance and self-processing mill with broken particles are mostly spherical particles, the surface of the dry-cleaning, easy binding agent.

green silicon carbide Application of steel fiber reinforced concrete

Application of steel fiber reinforced concrete 

Because of the superiority of steel fiber reinforced concrete can make in building structures, bridges and bridge engineering, railroad ties, and mine shaft, traffic tunnels, underground waterjet abrasives‍ cavern support, military engineering and repair and reinforcement structures, underwater etc. have been widely used. 

In the field of building construction, mainly for house building structures, seismic node industrial and civil construction, and rigid roof, underground water engineering. House building structure, mainly due to the steel fiber  steel fiber for concrete reinforcement‍  reinforced concrete with isotropic effect, so it is an ideal material for a variety of complex Purchased components to withstand stress; node in seismic areas, mainly the use of steel fiber reinforced concrete instead of stirrups to solve stirrups too dense seismic node problem; mainly in terms of the rigid application of its roof instead of steel or steel mesh for roofing rigid waterproof layer; underground waterproofing works, steel fiber reinforced concrete with a waterproofing agent to form the excellent performance of moisture, crack resistance , wear-resistant materials. 

Structural engineering and bridge deck, the main advantage of its high toughness, excellent tensile, flexural, impact, fatigue and crack control performance. Steel fiber reinforced concrete not only cubic boron nitride‍  improve the carrying capacity of the bridge, and the bridge structure to reduce the weight, saving the amount of steel and concrete and masonry piers and so the lower the number the effect is obvious, and has achieved significant economic benefits. 

black silicon carbide Mechanism of action of fiber reinforced concrete

Mechanism of action of fiber reinforced concrete
According to theoretical and experimental results at home and abroad, compared with ordinary concrete, mechanical properties of steel fiber reinforced concrete significantly improved tensile strength and can be increased by about 2-fold, bending strength is 2.5-3.5 times that of ordinary concrete flexural strength, sandblasting material  improve the impact strength is more obvious, generally up to 5 times more than ordinary concrete, and even up to 20 times.
Currently, the mechanism of steel fiber reinforced concrete, there are two different interpretations. One is the fiber spacing mechanism proposed by waterjet abrasives  the United States Rmuald; One is composite mechanism England Swamy, Manga and others made. Here we analyze the main fiber spacing mechanism.
Fiber spacing mechanism is based on the basis of linear elastic fracture mechanics description of a constraint fiber up to the occurrence and development of cracks. The mechanism that in the concrete originally flawed, desire to improve the strength of this material, it must be possible to reduce the level of defects, improve toughness and reduce stress concentration factor inside the crack tip.

The model assumes that the fiber was pulled in the direction of stress in the concrete distribution board (spacing S), crack (radius a) present in the four walled steel fiber center, at this time, since the bond stress distribution caused by the tensile stress () produced in the vicinity of the fiber and  Fused zirconia mullite the adjacent ends of the crack, the crack development plays a role constraints. If you set the internal tensile stress cracks in the ends of the stress caused by the concentration factor is, while the crack ends adjacent the bond stress distribution generated with opposite meanings, from the binding effect of the stress concentration factor, the total stress factor will be reduced                                                 

green silicon carbide mproved strength against the fold

mproved strength against the fold
Bending steel fiber concrete action against increased. Because the substrate by interfacial bond strength to transfer loads to the steel fibers, and steel fibers can sandblasting material be constrained to extend the cracks and Trans cracks pass internal forces. Then steel fiber and the matrix as a whole share the load, the bearing capacity significantly increased when the steel fiber and when the concrete matrix interfacial bond strength between the limit is reached, then the power of the largest cracks steel fibers from  waterjet abrasives fiber anchoring the shortest, by the open so that, in turn pulled out from the matrix, the carrying capacity of steel fiber reinforced concrete decreases system to Fused zirconia mullite destroy Thus the greater the content of steel fibers, the fiber pull-out energy consumption greater binding effect and effect on fracture, the stronger the transfer internal forces and destroyed, so the better the reinforcing effect.

white aluminum oxide High temperature refractoriness

High temperature refractoriness                                                                                                                          Refractory cone bend test under high temperature and poured extent, depending on the number of liquid and solid phase ratio of the dispersion liquid and the viscosity of  Fused zirconia mullite  the high-melting crystalline phase. Typically the cone reaches refractoriness was most similar to 70 inclusive to 80%, the liquidus viscosity of about 10 ~ 50Pa · s, and varies with the material. Therefore, unless the level considered refractory refractoriness and determination conditions, particularly with the test composition and the cone size and the rate of temperature increase of some material other than the relevant measurement atmosphere, mainly by the chemical and mineralogical composition of the material is controlled. Refractories composed of two components from a variety of single terms, depending  synthetic diamond  on the level of the melting point of the compound. And the multi-component constituted by a refractory material, the main component and the ratio depends on the number of his ingredients. Impurities seriously reduce refractoriness material. Such as Al2O3, alumina refractories content of 20 to 80% between, the refractoriness t can be approximated with Al2O3 and estimate the percentage of impurities R, ie t = 1580 +4.386 (Al2O3-R). Therefore, to improve the  white aluminum oxide  refractoriness of the refractory must increase the number of principal components and the main crystal phase and to minimize impurities.
Refractoriness determined in accordance with standard test methods refractoriness refractory GBT 7322-2007