green silicon carbide chemical stability

 high thermal conductivity, thermal expansion coefficient, good wear resistance, except for the abrasive used, there are many other uses, synthetic diamond 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) CBN abrasive grit 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 semiconductor, resistant to oxidation at high temperatures.

the hardness between corundum and diamond

Formula SiC, the hardness between corundum and diamond, corundum higher mechanical strength can be used as an abrasive and certain other industrial materials. The successful development steel fiber for concrete reinforcement  of industrial use of silicon carbide in 1891, is the oldest artificial abrasive. Although meteorites and the Earth's crust in a small amount of silicon carbide exists, but has not yet been found for the exploitation of mineral resources.black silicon carbide In addition, silicon carbide heating elements are also used extensively for  fused zirconia mullite  the production of silicon carbide.
The great hardness of silicon carbide having excellent thermal conductivity, is a semiconductor, is resistant to oxidation at high temperatures.
Since the stacking sequence of α-SiC crystal structure different from carbon and silicon atoms to constitute a number of different variants have been found more than 70 species. β-SiC into α-SiC at the time of over 2100 ℃.

Green silicon carbide is suitable

Green silicon carbide is suitable for grinding wheel to the outer code processing GC carbide, glass, ceramic and metallic materials, is also used for a semiconductor material, Glass beads  high temperature silicon carbide heating element, far-infrared source substrates and the like.
According to the shape can be divided into flat-shaped grinding wheel, bevel grinding, cylindrical grinding wheels, cup wheels, disc wheels, etc.; binding agents can be classified according to the ceramic wheel, resin wheel, rubber wheel, metal grinding wheel.
Wheel after working synthetic diamond for a period of time, should be trimmed to restore grinding performance and correct geometry.
The main characteristic parameters of the abrasive wheel, the viscosity, hardness, binders, shape, size and the like. Since the wheel is usually working at high speed.

black silicon carbide chemical stability

Black silicon carbide and silicon carbide green silicon carbide two common basic varieties, Silicon carbide due to 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 turbine impeller or wall, can improve the wear resistance and extend the life of 1 to 2 times;  black silicon carbide for advanced refractory material, heat shock, small size, light weight high strength, good energy saving effect. A low-grade silicon carbide (containing about 85% SiC) is an excellent oxygen scavenger, which can be used to accelerate the speed of the steel brown fused aluminum oxide  and to facilitate control of the chemical composition, to improve the quality of steel. In addition, silicon carbide heating elements are also used extensively for the production of silicon carbide.
The great hardness of silicon carbide having excellent thermal conductivity, is a semiconductor, is resistant to oxidation at high temperatures.

green silicon carbide Grit Features

Grit Features: moderate hardness, toughness, impact resistance, can be repeated several times using continuous, long life, good rebound, strong adhesion, clean up fast low consumption of sand, not broken, green silicon carbide clean up the workpiece brightness, good technical results, this product is processed through the metal surface cleanliness of up to international standards. Surface roughness of 25--150um, thus increasing the contact surface of the metal surface to improve the surface adhesion smear of refined metal surface hardening metal structure, with a very significant economic benefits,waterjet abrasives  is the most advanced home and abroad, most ideal blast cleaning, descaling and enhanced quality materials. 

Grit raw material is high-carbon steel fused zirconia mulliteor alloy steel scrap material.

A direct use of scrap material preparation process grit.  sandblasting material  ‍Comprising the steps of:

(1) made ??of high carbon steel or / and alloy steel scrap material, into the quenching apparatus for heating quenching;

(2) heating after quenching scrap material into the crusher, get grit semi;

(3) The grit semi sorting that prepared the finished grit. Grit production method of the present invention to reduce the traditional production process must grit cast steel shot into the scrap smelting and manufacturing processes pill, saving the cost of production. ‍

white aluminum oxide Fused brick

Fused Fused zirconia corundum brick brick brick , also known as the abbreviation is AZS, is based on three chemical composition Al2O3-Zr02-Sio2 ternary phase diagram , according to their order of how much content , Al2O3 take A, Zr02 take Z, Sio2 take S, using the abbreviation for national standards , such as 33 cast AZS bricks, abbreviated as AZS-33 #, 36 cast AZS bricks, abbreviated as AZS-36 #, white aluminum oxide‍ 41 cast AZS bricks, abbreviated as AZS- 41 # .

Fused brick manufacturing process will be a selection of zircon sand and industrial alumina powder with 1:1 , plus a small amount of NaZO ( in the form of sodium carbonate is added ), B20: ( in the form of boric acid or borax added ) flux , mixed uniform , after the 1900 ~ 2000 ℃ melt cast molding , can be prepared containing zr0233% of the cast slabs . On this basis , the use of part desilication zircon sand as raw material , can be obtained with ZrO2 36% ~ 41% of the cast slabs . gaogangyuzhuan corundum brick (z irconia-eorundumrefraetory brick) using industrial alumina powder and a selection of zircon sand as raw material , ZrO2 content is made ??of 33% to 45 % of the refractory products . White fused aluminum oxide‍ Fused zirconia corundum brick is mainly used in the glass industry furnaces , electric glass furnace, the steel industry 's slide, sodium silicate industry kilns and other high temperature erosion -resistant refractory kiln

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                                           

Abrasive blasting range of applications

( A ) coating the workpiece , the workpiece can blasting treatment before bonding the surface of all dirt or rust removed and the surface of the workpiece is important to establish the basis of the drawings ( which is usually called the matte side ) , and can be through the exchange of different size abrasive , abrasives such as abrasive Chin achieve varying degrees of roughness , greatly improving the work with paint, coating material adhesion. Or so pieces of adhesive bonding stronger , better quality .
(B ) casting matte , sandblasted after heat cleaning and polishing the workpiece can clean up the castings and forgings , all the dirt surface after heat treatment (eg, oxide , oil, and other residues ) , and to improve the surface finish of the workpiece polishing can make mold for grinding wheel workpieces exposed metal color uniform , so that the workpiece looks more beautiful, beautiful.
(C ) machined parts deburring and surface blasting can clean up the surface to beautify the tiny glitches, and make the surface more smooth , eliminating the hazards glitches and improve the quality of the workpiece. And sandblasting can play a small fillet at the junction of the workpiece surface , the workpiece is even more beautiful, more sophisticated .
(D ) to improve the mechanical properties of the parts after sandblasting machine parts , can produce a uniform fine uneven surface in parts of the surface , so that oil get stored , so that lubrication conditions improve and reduce the noise to improve the mechanical life.
(E ) light decoration effect for some special purpose parts, sandblasting can easily implement different reflective or matte . Such as stainless steel parts , plastic grinding , polishing , wooden furniture matt surface of jade , patterns frosted glass surface and texturing surfaces such as fabrics .

Diamond Case

Yuan Shi
December 2010, Japanese scientists
Cylindrical "Yuan Shi"
Successfully synthesized the world's cubic boron nitride hardest diamond, more than 1 cm in diameter, and strive to cooperate with the fastest production company said.
This is the result of a cylindrical diamond Ehime University researchers in Japan with Sumitomo Electric Industries, Inc. cooperation, was named "Yuan Shi", taken from "Ehime."
Tetsuo researchers into the boat, said Yuan stone is the world's hardest artificial diamond, diamond-hard, a lot more than ordinary, and therefore can be applied to many industrial activities were. "Yuan Shi can help people learn more about carbon elemental crystals under high pressure and temperature conditions deep in the earth formation; same time, as a kind of industrial supplies, its life expectancy is several times longer than ordinary diamond.

White corundum

White fused aluminum oxide powder is a high-quality raw materials, smelting by fused it with white color, high hardness, toughness slightly lower, high purity, excellent self-sharpening, grinding power, low heat, high efficiency , acid corrosion, high temperature resistance, good White fused aluminum oxide thermal stability and other characteristics, it is not only superior abrasive materials, and or advanced grinding, polishing materials, processed with abrasive it made ??for grinding carbon steel, high speed steel and a variety of stainless steel. It is also widely used in precision casting, steel sandblasting material fire-resistant, fire-resistant chemicals, 95 porcelain, decorative ceramics and porcelain, and other special daily use porcelain, as well as military, electronics and other high-tech industries.

Fused zirconia corundum brick

Fused zirconia corundum brick AZS fused zirconia corundum brick , also known as the abbreviation is AZS, is based on three chemical composition Al2O3-Zr02-Sio2 ternary phase diagram , according to their order of how much content , Al2O3 take A, Zr02 take Z, Sio2 take S, using the abbreviation green silicon carbide for national standards , such as 33 cast AZS bricks, abbreviated as AZS-33 #, 36 cast AZS bricks, abbreviated as AZS-36 #, 41 cast AZS bricks, abbreviated as AZS-41 #.
AZS bricks are fused with pure alumina and zirconia powder 65% , about 34% silica, zircon sand in the melting furnace in the power injected into the model of cooling a white solid formed , which facies helical structure of corundum and zircon stone and glass eutectoid phase composition , in terms of learning from the phase -phase and zirconium corundum stone ramp eutectoid phase , filling the glass with crystal between them .
Electric cast brick manufacturing process of the selection of zircon sand and industrial alumina powder with 1:1 , plus a alluvial garnet gbrasives small amount of NaZO ( in the form of sodium carbonate is added ), B20: ( in the form of boric acid or borax added ) flux , mixed homogeneous by 1800 ~ 1900 ℃ melted cast molding , can be prepared containing zr02) 33% of the cast slabs . On this basis , the use of part desilication zircon sand as raw material , can be obtained with ZrO236% ~ 41% of the cast slabs . googangyuzhuan corundum brick (z irconia-eorundumrefraetory brick) using industrial alumina powder and a selection of zircon sand as raw material , ZrOZ made ??content is 33 % to 45% of refractory products . Lead is mainly used in the glass industry corundum brick furnaces .

Fused brick

Fused Fused zirconia corundum brick brick brick , also known as the abbreviation is AZS, is based on three chemical composition Al2O3-Zr02-Sio2 ternary phase diagram , according to their order of how much content , Al2O3 take A, Zr02 take Z, Sio2 take S, using the abbreviation for steel fiber for concrete reinforcement national standards , such as 33 cast AZS bricks, abbreviated as AZS-33 #, 36 cast AZS bricks, abbreviated as AZS-36 #, 41 cast AZS bricks, abbreviated as AZS- 41 # .
Fused brick manufacturing process will be a selection of zircon sand and industrial alumina powder with 1:1 , plus a small amount of NaZO ( in the form of sodium carbonate is added ), B20: ( in the form of boric acid or borax added ) flux , mixed uniform , after the 1900 ~ 2000 ℃ melt cast molding , can be prepared containing zr0233% of the cast slabs . On this basis , the use of part desilication zircon sand as raw sandblasting material material , can be obtained with ZrO2 36% ~ 41% of the cast slabs . gaogangyuzhuan corundum brick (z irconia-eorundumrefraetory brick) using industrial alumina powder and a selection of zircon sand as raw material , ZrO2 content is made ??of 33% to 45 % of the refractory products . Fused zirconia corundum brick is mainly used in the glass industry furnaces , electric glass furnace, the steel industry 's slide, sodium silicate industry kilns and other high temperature erosion -resistant refractory kiln

Black silicon carbide Introduction

Silicon carbide is divided into black and green silicon carbide. Silicon carbide, also known as Moissanite. In The use of steel fibers contemporary C, N, B and other non-oxide refractory materials in high-tech, silicon carbide is the most widely used and most economical one. Can be called emery or refractory sand. Where: Black silicon carbide is quartz sand, petroleum coke and quality silica as the main raw material, smelting electric arc furnace. Its hardness between corundum and diamond, corundum higher Fused zirconia mullite mechanical strength, brittle and sharp. Silicon carbide, metallic luster, containing more than SiC 95%, greater than the intensity of green silicon carbide, but lower hardness, is mainly used for grinding cast iron and non-metallic materials

Black silicon carbide Introduction

Silicon carbide is divided into black and green silicon carbide. Silicon carbide, also known as Moissanite. In contemporary C, N, B and other non-oxide refractory materials in high-tech, silicon White fused aluminum oxide carbide is the most widely used and most economical one. Can be called emery or refractory sand. Where: Black silicon carbide is quartz sand, petroleum coke and quality silica as the main raw material, smelting electric arc furnace. Its hardness between corundum and diamond, corundum higher mechanical strength, brittle and sharp. Silicon carbide, metallic luster, containing more than SiC 95%, greater than the intensity of green silicon carbide, but lower hardness, is mainly used for grinding cast iron and non-metallic materials

Advantages fused mullite

Porous ceramic fibers, adhesives, mullite precursor gel, mullite nanocrystals Introduction mullite has good properties, such as high melting point, a small expansion, thermal shock resistance, true specific gravity is low, creep resistance high and good chemical stability [] -21. From a porous material mullite fibers prepared with high porosity, lightweight, low thermal conductivity, high permeability, synthetic diamond non-brittle, etc., with a wide range of applications in the chemical, metallurgy, environmental protection and other areas will have great social and economic significance _3_. In fiber porous ceramic fibers rely architecture into the hole between the point of contact with the adhesive connection between the fibers, so the degree of solid adhesive bonding for excellent performance full of ceramic fiber base, end-use properties of the product from a decisive role. Considering the substrate used for forming porous mullite ceramic fibers, such as a binder with a sintered mullite crystalline phase, its crystalline phase cubic boron nitride and microstructure fibers with mullite and consistent with the same thermal expansion factor, after forming the porous ceramic having better performance. This paper used mullite fibers bonded with a porous ceramic mullite ceramics preparation and structure analysis.

Use of silicon carbide

Silicon carbide has four major application areas, namely: functional ceramics, advanced refractories, abrasives and metallurgical materials. SiC coarse material has been able to supply a large number, can not be considered high-tech products, while high-tech nano-silicon carbide powder steel fiber for concrete reinforcement is impossible to form a short application of economies of scale.
⑴ as an abrasive, can be used for abrasives, such as grinding wheel, Whetstone, grinding, sand tile and so on.
⑵ as metallurgical deoxidizer and high temperature materials.
⑶ high purity single crystal can be used sandblasting material for the manufacture of semiconductor manufacturing silicon carbide fibers.
Main purpose: for 3-12 inch monocrystalline silicon, polycrystalline silicon, gallium arsenide, quartz and other wire cutting. Solar photovoltaic industry, the semiconductor industry, piezoelectric crystal engineering of industrial processing of materials.
For semiconductors, lightning, circuit elements, high-temperature applications, UV detector, structural materials, astronomy, disc brakes, clutch, diesel particulate filter, filaments pyrometer, ceramic film, cutting tools, heating elements, nuclear fuel , jewelery, steel, protective gear, catalyst carrier body and other fields.

Synthetic diamond

Artificially non-diamond carbon structure into a diamond structure carbon , and are formed by nucleation and growth of monocrystalline and polycrystalline diamond, or the fine-grained diamond sintered polycrystalline diamond at high pressure and temperature . An important example of this is the high pressure applied in the current research on the production .
From the viewpoint of thermodynamics , the decision diamond structure of graphite and other non- carbonaceous material into a diamond can Phase Transition of the latter must be less than the free energy mold for grinding wheel of the former . This phase transition under conditions of high pressure , high temperature or other components participating conducted . Certain pressure , temperature and component concentration can make the system can change, so that the valence electrons can be right at the statistical level of weight change accordingly . This electron transfer , and may be bonded to form a new state of the electronic structure, i.e., the phase transition occurred . If the energy change in favor of the occurrence of this change in the electronic structure of the solid , the pressure and temperature in the solid state phase transition occurs , or may occur in the molten or vapor state . This change steel fiber for concrete reinforcement of condition occurs in the melt , the statistical characteristics of the right bonding valence electron distribution corresponding decrease weight , the effect tends to disappear remote ordered atomic coordination number changes ; statistical weight and the weight of electronic excited state chemotaxis at increasing the role of short-range order corresponding enhancement. This condition occurs in the gas change is elemental electron energy level bonding between atoms or molecules of the compound tends to disappear and all the electrons are transferred to a single atom or molecule level up , so that the electron is re- excited state statistical weight more is increased. Thus, the synthetic diamond may be in a solid state , but also in the melt state and the vapor state conditions , depending on pressure, temperature and component concentration changes can be caused by factors within the system . From the kinetic point of view, but also requires a change in the rate of change in the appropriate carbonaceous materials such as graphite into diamond when . Phase change rate of the diamond nucleation rate and growth rate at the same time when the maximum value is the maximum .

Fused zirconia mullite nature

Also known as fused zirconia mullite fused mullite brick, commonly known as iron or iron brick tiles, consisting mainly of the mineral  refractory materials  (60% to 70%) of fused cast refractories, is a weak acid refractories. The main component of an alumina content of 65% to 75%, a silica content of about 25% of the total oxides of the other 5% to 8%. Cast of relatively dense  crefractory materials brick, refractoriness of 1730 ~ 1800 ℃, load softening temperature of the beginning of 1700 ℃, high temperature strength and wear resistance, corrosion resistance is strong. A low coefficient of thermal expansion. Thermal conductivity is higher, therefore, thermal shock resistance than other cast brick well. High bauxite, alumina and fireclay industries as raw materials, furnace melting, casting, annealing and made. Mainly used in glass melting furnaces and other industrial kilns

Refractories are generally composed of a number of body

Wherein the mineral phase can be divided into two categories , i.e. the crystal phase and the glass phase .
The main phase is the main structure of the products constituting the crystalline phase and the higher melting point . Nature of the main phase , during which the number and combination of state Fused zirconia mullite directly determines the nature of the products .
Matrix is the large crystals of the refractory aggregate or substances present in the gap . Matrix on the nature of products ( such as high temperature resistance characteristics and resistance to invasion ornaments ) plays a decisive impact. When using the products, often starting with damage from the matrix section , the use of adjustments and changes in matrix components products are effective measures to improve product White fused aluminum oxide  performance process .
The vast majority of refractory products ( except for a few extra high refractory products outside ) , their main phase and matrix components can be divided into two categories : one is a multi-component refractory products containing crystalline phase and glass phase , such as clay , silica bricks ; Another multi-ingredient products containing only crystalline phase , mostly fine matrix crystals, such as brick, chrome magnesia brick and other basic refractories . These articles in high temperature firing , a certain amount of liquid , but does not form a liquid phase upon cooling the glass , but the formation of a crystalline matrix , the main crystal phase cemented together , the matrix component is different from the main phase crystal .
Microstructure There are two types of refractory products . A is a silicate ( silicate mineral crystal or vitreous ) binding was cemented type crystal particles , the crystal particles from the other is directly integrated into the crystalline network interlace , e.g. purity brick, this type of structure directly bonded high temperature properties ( temperature mechanical strength , slag resistance or thermal shock resistance , etc. ) products far superior than the previous one ; therefore have to have broad prospects for development .

Green silicon carbide replacement process Precautions

Any wheel wear problems have some wear and tear of its requirements, wear a certain extent it is necessary brown fused aluminum oxide to replace the new wheel. Not in order to save material, it requires the use of ultra-wear, which is a very unsafe illegal behavior. A general rule, when the wheel wear to a larger diameter than the diameter of 10mm chuck should be replaced with new wheel. Valid questions from the Treasury brought out a new wheel is not necessarily qualified wheel, new wheel even buy from the manufacturers are not necessarily qualified wheel. Any wheel has its certain expiration date, within the validity period of use, it is qualified wheel; than Glass beads valid use, it is not necessarily qualified wheel. Rules of order "wheel should be within the validity period, resin and rubber bonded grinding wheel rotating storage must be approved by the test, those who pass the year before use." Texture problems with the process, if you find a local wheel cracks, should immediately stop using and re-replacement of the grinding wheel, grinding wheel to avoid crushing injury accident.

White alumina

Alumina is a white aluminum oxide powder as raw material in electric arc furnace at high temperature smelting together, the main chemical ingredient of Al2O3 content is generally higher than 98%, higher brown fused aluminum oxide than corundum hardness, toughness lower than corundum, better cutting performance. It is made ​​by grinding, suitable for grinding hardened alloy steel, high speed steel, high carbon steel. Fine-grained powder suitable for high-precision optics polishing and polishing. Others include precision grinding wheels, precision glass, crystal polishing, and fine ceramics can be used

Preparation and application of alumina:

1, α-type crystal structure as the main method for manufacturing a film of alumina, α-type  White fused aluminum oxide  structure as the main body containing the alumina coating film
2, the method for manufacturing α-alumina powder
3, the manufacturing method and the α-alumina powder of α-alumina powder obtained by the method
4, α-alumina powder and production method thereof
5, α-alumina powder and its manufacturing method
6, α-alumina,  waterjet abrasives the manufacturing method
7, α-alumina pellets for preparing
8, preparation of α-alumina nano powder
9, α-alumina powder and its manufacturing method
10, α-alumina powder manufacturing method
11, β-alumina, a method for preparing
12, γ-alumina, a method for preparing
13, θ-alumina, in place of the monolithic catalyst carrier coated
14, the joint production of alumina and calcium aluminate cement method Bayer
15, Bayer alumina production process red mud suspension fluid gasification process

What is a green silicon carbide

Green silicon carbide and silicon carbide powder production is basically the same, just different requirements for raw materials. Green silicon carbide based petroleum coke and quality silica as the synthetic diamond raw material, add salt as an additive, smelting electric arc furnace, was smelted into cubic boron nitride purity crystals, hardness, hardness between corundum and diamond between mechanical strength higher than corundum.

Characteristics of 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 turbine impeller or cylinder body wall, can improve the wear resistance and extend the life of 1 to 2 times; for advanced refractory material, 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), with excellent thermal conductivity, is a semiconductor, resistant to oxidation at high temperatures.

ntroduction of silicon carbide?

Silicon carbide (SiC) with quartz sand, petroleum coke (or char), sawdust from electric arc furnace smelting. In nature there are also rare silicon carbide mineral moissanite. Silicon carbide, also known as Moissanite. In contemporary C, N, B and other non-oxide refractory materials in high-tech, silicon carbide is the most widely used and most economical one. Can be called emery or refractory sand. Silicon carbide is with quartz sand, petroleum coke (or coal tar), wood (green silicon carbide need to increase the production of salt) and other raw materials in high temperature resistance furnace smelting. At present China's industrial production of silicon carbide is divided into two kinds of black silicon carbide and green silicon carbide, are hexagonal crystals, accounting for 3.20 to 3.25, microhardness 2840 ~ 3320kg/mm2.

What material temperature

High temperature resistant material comprises a refractory material , an inorganic compound , there are polymer materials . More usually refers to the ability of the refractory 1580 ℃ temperature inorganic material. They are built furnaces , high temperature combustion and other needed supplies . Generally made ??of quartz sand , clay , magnesite, dolomite and other raw materials , high temperature thermal insulation coatings Chi Shing , is a component of the inorganic coating , the temperature in the range of -80-1800 ℃, thermal conductivity 0.03W/mK, can inhibit the body temperature and low-temperature heat radiation and conduction body heat , body temperature can be maintained for 70% of the heat is not lost . Chi Shing paint on surfaces coated 8mm 1100 ℃ high temperature insulation coating , the surface temperature can be reduced from 1100 ℃ to less than 100 ℃. In addition there is high temperature resistant insulation coating insulation , light weight, easy construction, long service life , high temperature resistant inorganic materials can also be used as acid crosslinking agent, attachments body firmly. Such as refractory cement , magnesia brick and so on. Broadly speaking , an inorganic fire- resistant material refers to those compounds with high hardness and brittleness , resistance to chemical corrosion , and the melting point of 1500. The main two types of intermetallic compounds with non-metallic and non-metallic compounds. The former such as tungsten , molybdenum , tantalum , niobium , vanadium , chromium , titanium, zirconium and rare earth metal refractory metal borides, carbides , nitrides , silicides, phosphides , and sulfides ; latter as boron carbide , silicon carbide , boron nitride , silicon nitride, boron phosphate , silicon phosphate and the like. The latter has a very important purpose , high temperature refractory material can be used (e.g., abrasives , molds, nozzles, high temperature thermowell ) , heat-resistant material ( such as structural components of the rocket, nuclear engineering materials , heating elements ) , electrical materials ( such as high temperature thermocouple, ignition electrode ) , also used as a chemical resistant material and a rigid material. Heat-resistant polymer film can be used as high temperature insulation materials, high temperature fiber , high temperature coatings, high temperature adhesives. According to the time of high temperature , high temperature materials is divided instantaneous temperature materials and a longer time . 1000 ~ 10000 ℃ former ability seconds to minutes . Ablative materials which are also high-temperature materials. For example, in 300 ~ 600 ℃, the air can maintain its mechanical strength, resistance to chemical corrosion.

The results of refractories

Acidic refractory silicon oxide as the main component , commonly used silica brick and clay . Silica brick containing 94% silica siliceous products, raw materials used are silica, silica brick scrap , with its strong acid slag corrosion resistance , high softening temperature under load , the volume does not shrink after repeated firing , even a slight expansion ; but its
vulnerability to erosion of basic slag , thermal shock resistanceis poor. Mainly used silica brick oven , glass melting furnaces , steel furnaces and other acidic thermal equipment . To fire clay brick as the main material containing 30% to 46 % alumina , is a weak acid refractory, thermal shock resistance, corrosion
resistance to acid slag has wide application .
Neutral alumina refractory oxide, chromium oxide or carbon as a main ingredient. Containing more than 95% of alumina corundum products is a wider use of high-quality refractory materials.
Chromium oxide as the main component of chromium slag bricks for good corrosion resistance , but poor thermal shock resistance , low temperature load deformation temperature . Carbon- carbon refractory bricks, graphite products and silicon carbide products, low coefficient of thermal expansion , high thermal conductivity , good thermal shock resistance , high temperature strength , resistance to acid and salt erosion, especially with a weak acid better resistance, metal and slag from wetting light . Widely used as a high-temperature furnace lining material , also used in petroleum, chemical autoclave liner.
Basic refractory magnesia , calcium oxide as the main component , is used magnesia brick . Magnesium containing more than 80 % to 85 % of the brickalkaline slag and iron slag has good resistance , high refractoriness than clay and silica brick . Mainly used for open-hearth , basic oxygen furnace , electric furnace, high temperature and non-ferrous metal smelting equipment and some equipment .

Refractory role

Refractories used in various fields of steel, nonferrous metals,glass, cement, ceramics, petrochemical, machinery, boilers, light,power, military and other national economy, industrial production is to ensure that these essential operational and technical development of basic materials, plays an irreplaceable role in the development of high-temperature industrial production.

Performance Refractories

White fused corundum is a high-grade refractory materials, color white, dazzling crystal, with a large volume density, low porosity, etc., can effectively improve the volume stability and thermal shock resistance of the material. White fused corundum is the main raw material for production of high uncertainty and shaped refractories for large ladle castable, high-grade iron trough castable, gunning mix, precast and monolithic refractories such as corundum bricks, corundum and mullite corundum quality cartridge body, refining a variety of corundum corundum plug porous brick, the overall composite nozzle spray gun and high temperature industrial furnace lining material and other products. Widely used in iron and steel, cement, ceramics, abrasives, petrochemical and other industries.

white aluminum oxide,black silicon carbide,green silicon carbide

In practical applications, such as requiring heat shock stability, structural spalling resistance, while resistance to slag erosion and high thermal conductivity properties, silicon carbide refractories should be preferred. From the development trend, silicon carbide monolithic refractories, not only in metallurgy, building materials industry has a pivotal position, with the introduction of large-scale circulating fluidized bed boiler and the transformation of a small power plant (gradually transformed into a clean burning heating boilers and garbage incinerator) silicon carbide monolithic refractories in the power sector will also be more widely applied. We would like to be able to develop their advanced performance, adapt to the development of amorphous silicon carbide refractories in various industries.