Furnace with rails and monolithic refractories

Unshaped refractories having a particle size gradation of the aggregate and the Sic Refractory powder, a binder, a refractory mixture of additives, also known as bulk refractories. Equipment for thermal lining, without firing process, the direct use baking. With firebrick, compared with a simple process (due to eliminating the firing process), energy conservation, low cost, ease of construction and other features of mechanization. Use of thermal equipment on some better results than firebrick.
Currently, there is no domestic water-cooled furnace uses a rolling silicon carbide corundum a Calcium silicon, rolling mill furnace taphole platform uses a high alumina ramming mixes. A silicon carbide and high alumina corundum ramming material at high temperature heating of billets contain more silica. Slab surface iron oxide and silica will form the furnace temperature below the melting point of iron olivine, resulting in poor wear resistance of high temperature refractory, low-life, easy slag within the furnace.

Confront refractory additives added to improve the mechanical properties

Abstract: The effect of ZrSiO4-3mol% Y2O3 additives on the mechanical properties of MgO-MgAl2O4 Sic Refractory and thermal stress parameters. Research shows that the mechanical properties of the additive significantly improved, R-Rst parameter has increased to 2 to 3 times of the raw materials. Improve the mechanical properties of refractory and thermal performance parameters depend on: the (1) ZrSiO4 Mg2SiO4 prevent decomposition of crack generation and propagation; (2) micro-cracks intersect within a short distance of propagation; (3) In case of micro-cracks to vent or ZrO2 grains produced by the silicon carbide powders of ZrSiO4 (Y2O3 and ZrO2 grains distributed in the same position) will be absorbed or extended; (4) after the introduction of ZrSiO4-Y2O3 transgranular cracking and intergranular cracks exist; (5) to increased density; (6) MgO grain size significantly smaller.
Category Industrial Technology> Chemical Industry> Portland Industrial> Industrial Refractories> Refractory Products> unshaped refractories> Spray Paint
Keywords MgO spinel refractory zircon mechanical properties of Y2O3

Impact SM superplasticizer and zircon refractory castable

Abstract: SM superplasticizer on castable flow values ​​and mechanical properties, as well as adding zircon aluminum powder for refractory castable material impact on the residual thermal shock flexural strength. The results showed that in the test range increases with SM castable flow amount increases, the volume density, reduced porosity, compressive strength, flexural strength increases; Zircon with increasing thermal shock 15 times the residual flexural strength increases first and then decreases.
Brown Corundum Industrial Technology> Chemical Industry> Portland Industrial> Industrial Refractories> Refractory Products> unshaped refractories> castable
Keywords SM superplasticizer zircon refractory castable

Progress of unshaped refractory castable

Introduced a monolithic refractories way to cast construction abrasive material - castable, and according to the author of the latest research findings and new products in recent years about the casting material preparation, application, etc., systematic exposition of coke gem-based castable, bauxite-based castable, mullite-based castable, corundum based castables, magnesia castable, lightweight insulation castable and research progress and performance of acid and alkali resistant castable. On this basis, the development trend castable.
Also known castable Sic Refractory castable: a refractory material joined by a certain amount of granular and powdered materials made ​​binders. With higher liquidity, apply to casting molding way monolithic refractories. Compared with other monolithic refractories, binders and moisture content is higher, better mobility, so a wide range of applications without stereotypes refractories can be used for selection of materials and binders based on conditions of use. Either directly poured into the lining of the body to use, and available method of casting or real shock made ​​use of prefabricated blocks.

Modulation of alumina cement refractory castable development

Abstract: The development of Sic Refractory containing fine particles are added to the agent alumina cement castable modulation. Agent is used to join aluminum thermal decomposition of ferrochrome from slag and high alumina screenings. Such castable studied the physical and mechanical properties and thermal properties.
Spinel is magnesium Alumina Oxides spinel mineral composition, because it contains magnesium, iron, zinc, manganese, etc. elements, which can be divided into many kinds, such as aluminum spinel, spinel iron, zinc spinel manganese spinel, chrome spinel. Because it contains different elements, different spinel can have different colors, such as magnesium spinel between red, blue, green, brown or colorless; zinc spinel was dark green; iron spinel black and so on. Spinel octahedral form or glassy hard particles and lumps. They appear in igneous, metamorphic and granitic pegmatite limestone. Some pretty transparent and color as spinel stones, some as magnetic iron. Using artificial methods already create over 200 varieties of spinel.

Artesian refractory castable microstructure

Abstract: By adding the alumina spinel observed gravity nano-Alumina Oxide refractory castable particles at different temperatures in the microstructure and phase composition, study the physical and mechanical properties. The results show that the addition of nano-alumina material has a significant effect on the gravity refractory castable physical and mechanical properties. With the increase of the castable composition of the nano-alumina particles, the mechanical strength at different temperatures has been greatly improved. This indicates that nano-aluminum powders particles can affect the formation phase after firing. In common sample fired at 1500 ℃ found CA6 flaky crystals are formed on the plate-like alumina and spinel grain boundaries. Nano-alumina particles of the sample was added, in a lower temperature (1,300%) is formed CA6 phase.
[Classification] [Industrial Technology]> Chemical Industry> Portland Industrial> Industrial Refractories> Refractory Products> unshaped refractories> castable
Key words microstructure and mechanical properties Al2O3 spinel refractory

Adding aluminum-magnesium aluminum thermal properties of refractory castable

Summary : Overall the ladle lined with high Alumina Oxides castable aluminum powder can be added to improve its thermal properties, such as heat resistance and resistance to thermal shock resistance burst processing. Other mixtures of water and aluminum powder (magnesium oxide , bauxite cement ) mixing due to the formation H: gas permeability can be formed even cast material after casting vent . Metallic aluminum powder was determined to join the Department of A12O3-MgO castable burst resistance and thermal shock resistance of the research work carried out in the course of the trial . On the whole 300t ladle lined with castable A12O3-MgO conducted several tests, the results showed that the use of such material can improve the thermal casting performance and extend the life of the ladle in the ladle the whole lining.
aluminum powder, commonly known as " silver " , i.e., the silver metallic pigments , a small amount of lubricant is added to pure aluminum foil , crushed by ramming Chance squamous powder , and then polishing is made . Aluminum is light, floating force, hiding power, light and heat reflective properties are good . After treatment, can also become a non -leafing aluminum . Aluminum can be used to identify fingerprints , you can also do the fireworks . Due to extensive use of aluminum , the demand for large , multi-species , it is a large class of metallic pigments .

Refractory one project won the national invention patents

Abstract: Steel Refractories Co., Ltd. "back seam aluminum powder reduction cell sidewall filled with gravity casting material" project by the State Intellectual Property Office patent licensing. This invention proposes a design specifically for aluminum cell, the cell is filled between the shell and the side wall slot gap using gravity casting material. The monolithic refractories can improve electrolytic tank and the side wall of life, not high-temperature firing, and can achieve rapid casting, Sic Refractory field is energy efficient environmentally friendly materials.
Category Industrial Technology> Chemical Industry> Portland Industrial> Industrial Refractories> Refractory Products> unshaped refractories
Keyword artesian invention patents monolithic refractories castable SIPO electrolytic cell design channel

With alkali castable SiC amount of cement kiln

Different binders for Sic Refractory Abstract: waste ceramic powder, Guangxi white clay, silicon carbide, silicon powder as the main raw material, calcium aluminate cement as binding agents, add water and alkali configured castable. By adjusting the amount of added silicon carbide, silicon carbide impact study alkali castable and alkali erosion mechanism castable. The results show that: with the addition of calcium silicons increased sample volume density, compressive strength and flexural strength increased first and decreased sample surface oxidized layer of dense oxide film to prevent the erosion of alkali vapors when add 6% -8% of silicon carbide, alkali grade samples reached level, alkali erosion capacity increased significantly.
Category Industrial Technology> Chemical Industry> Portland Industrial> Industrial Refractories> Refractory Products> unshaped refractories
Keywords SiC Alkali castable

Effect of different binders for refractories description

Therefore, we must be selected for the workpiece material properties, in order to abrasive material good results. Binding agent must have the following properties: high strength, high heat resistance , a suitable hardness, small consumption of grinding , grinding efficiency , the surface roughness of the machined workpiece is better , fillers must be economical, but can be dissolved acid or base , to facilitate recycling . Superhard abrasive material is used as a binder resin material , phenolic resin is widely used , in addition to the epoxy resin , a novel phenol resin, a polyurethane resin, a polyimide resin, and bakelite powder. Brown Corundums can be classified according to the type : inorganic binder and organic binder . Inorganic binders include vitrified , metal bond , magnesite binding agent. Organic binder resin binders include rubber binder. Resin binder itself has good flexibility and polished , the formation of abrasive , still has a good self-sharpening , clogging, less trimming , and high grinding efficiency, low grinding temperature, surface grinding finish, so the wide range of applications . Combine to form a diamond abrasive resin bond diamond abrasive, often applied .

Effect of different binders on the rheological properties of monolithic refractories

calcium silicon: unshaped refractory binder definition and classification , introduced the use and application of the principles of various monolithic refractories binder , a detailed analysis of the different binding agents on the rheological properties of monolithic refractories , and analyzes the application status and future trends unshaped refractory binders discussed.
Category Industrial Technology > Chemical Industry > Portland Industrial > Industrial Refractories > Refractory Products > unshaped Sic Refractory
Keywords unshaped refractory binder rheology
About binder binding agent is a combination of various types of abrasive bonding agents and abrasive materials . Bonded Abrasives usually ceramic , resin, rubber, magnesite four categories binders . Binding agents can be divided into inorganic binder and organic binder . Superhard abrasive material constituting the binder resin is a thermosetting resin as a binder with a variety of fillers , the nature and amount of the number of the various components of the binding agent on the physical properties , mechanical properties and grinding performance have a great impact .

Development of recycling technology of refractory iron production

Sic Refractory meets the conditions of use of different devices There are many varieties and different quality. From the form of points, there are stereotypes refractories (refractory bricks) and unshaped refractories (casting material, injection materials, etc.). Iron and steel industry is large consumption of large industrial refractories, refractory these limited resources to build a recycling-oriented society, is an increasingly important issue in the future.
Category Industrial Technology> Chemical Industry> Portland Industrial> Industrial Refractories> Refractory Products> sandblasting abrasive refractories
Keywords unshaped refractory recycling technology development and production of iron and steel industry equipment and more varieties of material resources
Engaged in the production of means of social wealth of human activities and processes, including material wealth and spiritual wealth creation and people's own fertility. Also known as social production. Narrow sense refers only to create material wealth producing activities and processes.

Develop countermeasures and suggestions magnesia refractories

magnesite refractory to magnesite, seawater magnesite and dolomite as raw materials, mainly periclase crystal phase , magnesium Alumina Oxide content of more than 80% of the refractories. Belong to basic refractories . Its products can be divided into metallurgical magnesia and magnesia products into two categories. Depending on the chemical composition and metallurgical purposes can be divided into magnesia brick, silica brick magnesium , magnesium aluminum bricks, magnesium , calcium brick, magnesia carbon bricks , and other varieties . Its performance is greatly affected CaO/SiO2 ratio and impurities. The high purity magnesia brick load softening point and thermal shock resistance are much higher than the general magnesia brick as well. High refractoriness of basic slag and iron slag has good resistance , is an important high-grade refractory . Multi magnesia products produced by sintering , the calcination temperature is generally between 1500 ~ 1800 ℃, in addition , chemical binding agents can be added , and the unshaped refractories made ​​of unfired . Mainly used for open-hearth , electric furnace, oxidation converter, nonferrous metal smelting furnaces , cement kilns and kiln calcination basic refractories . Since the main origin of magnesite in southern Liaoning , namely Liaoning Haicheng City , Dashiqiao , Xiuyan County , Phoenix City and other places. So the area is rich in magnesia Sic Refractory materials - magnesia , including sintered magnesia and fused magnesia , is currently the world's richest regions , where there are many companies producing magnesia refractories .
Magnesia refractories production resources be required , and the resource has a comparative advantage . Development of the steel industry, requires a lot of magnesia refractories , magnesia refractories industry therefore has a broad market prospect. Through the planning and layout , strengthen management, implementation of industrial agglomeration, conducted a series of measures such as deep processing industry to promote the development of calcium carbide industry.

Impact of nanomaterials on refractories

Reduce the cost of production of clean steel mills continue to pursue each . Steelmaking Sic Refractory plays a key role in this regard , therefore , refractory facing greater challenges , in order to resist the harsh operating conditions , such as various types of high-speed steel casting , cold casting , etc., need to design a suitable refractory . Focus of this article is the key issue refractory products , such as increased erosion resistance Cypriot club head and submerged nozzle slag line , as well as to improve the high temperature strength of the product and so on . By introducing different proportions in the form of nano- oxide and non-oxide materials research special organic binding agent , developed the desired product. Through research, the final design of the casting process to match the low-cost products .
Discusses the specific requirements of calcium silicon refractory clay construction performance , sample tests conducted in accordance with the existing national technical standards, with a level of granularity and performance construction materials to give the agents studied. Ultimately concluded that a reasonable level of granularity is the oven with excellent access to basic construction performance with siliceous fireclay . You must add water-soluble organic and inorganic additives in combination , in order to make good fire clay construction performance .

Silicon carbide refractories explanation

Studied the clay bonded black silicon carbide refractories performance. SiC sintered at 1 500 ℃ preparation containing 20% -60% SiC , the clay clinker and clay compacts . Analysis of the sintered compacts of physical, mechanical and fire-resistant properties, and discusses changes in phase composition . Containing 20% SiC and 40% SiC refractory material having a certain load at a high density , high refractoriness , and has good corrosion resistance , is often used in furnace lining . In the ceramic industry, with 40% SiC and 60% SiC refractories , as one of the high content of SiC , under certain load has good thermal shock resistance , oxidation resistance and refractoriness , it is often used as kiln burning tank cars and use .
Refractories Refractoriness of not less than 1580 ℃ for a class of inorganic non-metallic materials . Refractoriness is the refractory cone specimen in the absence of load cases, resistance to high temperature without melting down the softening temperature in Celsius . Sic Refractory materials are widely used in metallurgy industry , chemical industry , petroleum, machinery manufacturing, silicates , power , etc., the largest amount in the metallurgical industry , accounting for 50 % to 60% of total production.
Statistical data as a processing methods and techniques in the refractory industry has been widely used. Take it to the next production of refractories and refractory good run important decisions for the smooth conduct of refractories acceptance sampling for scientific refractory to draw final conclusions , made ​​an indelible contribution.

Rare earth application in aluminum construction profiles

1, the rare earth application in aluminum powders construction profiles
In a typical civil construction in 6063 aluminum alloy profiles, add the content of rare earth range with 0.17% ~ 0.25% advisable, too many to join can have adverse effects on various performance instead. Rare earth on the mechanical property of 6063 aluminium alloy, the processing performance had a significant improvement in the function, after deformation profiles tensile strength can be increased by 5% ~ 10%, and hardness increased by 8% or so, elongation is improved. And can reduce rod extrusion temperature and improve extrusion speed. The study also found that after adding the rare earth elements 6063 Alumina Oxides ation coloring, film thickness, film can obviously increase the hardness and gloss, and improved the corrosion of acid, alkali and salt. All in all, 6063 aluminum after adding suitable amount of rare earth, thus refine microstructure, colour and lustre is uniform, beautiful, durable, deeply user welcome.
2, rare earth application in aluminium alloy wire netting
Rare earth aluminium alloy window screening, in strength, corrosion resistance, brightness, drafty, processability and cost, etc., are better than that of the same type without rare earth aluminium alloy wire netting, so for a wide range of applications. AnLiu window screen factory, LuJiang piston factory, for example, such as the production of rare earth aluminium alloy window screening, has been popular at home and abroad.

The comparison of two kinds of rare earths

1, re - Alumina Oxides alloy in the middle
Single rare earth metal chemical is high, easy oxidation burning loss during smelting, storage and transportation is not very convenient, cost is high, and high melting point, density, not easy to add to the aluminum. In most cases, therefore, are among the prefabrication of the rare earth - aluminum alloy, not only can reduce the oxidation burning loss, reduce the cost, and convenient transport. Join, simple and safe operation, and components are easy to control, available composition is stable, reliable quality of the alloy.
2, rare earth application in high purity aluminum powder capacitor
Containing rare earth high purity aluminum special aluminum foil, is an ideal new material in the low production of electrolytic capacitors. Some capacitor factory that, after adding trace rare earth in high purity aluminum, can dramatically increase the corrosion of aluminum electrolytic capacitor anode aluminum foil coefficient K, and the strength, capacitance is increased significantly. Made significantly smaller capacitor, the material has been batch used in some of the capacitor, and obtained a certain effect. But the effect mechanism of rare earth in them, have different opinions, is carrying out in-depth research.

Rare earth unique explanation

Rare earth and many of the unique physical and chemical properties to develop the alloy containing rare earth materials. Rare earth is not only a large number of used in military industry, silicon carbide powders, light industry, handicraft industry and transportation industry, also widely used as building materials, appliances and sporting goods such as family life.
The application of rare earth in conductive aluminum alloy, is now widely used in China, high technology is relatively mature, industrial value and economic benefit is good one area. High conductivity of rare earth alloy, usually refers to the pure aluminum, aluminum powder - magnesium - department of silicon and aluminum - magnesium alloy adding rare earth alloy, and aluminum zirconium - yttrium alloys. Mainly used in the manufacture of overhead transmission line, cable, sliding wire, wire core, general wiring, special purpose of fine lines and fine lines, aluminum wire. Its development soon, has risen from 315 V to 500 V on the high tension line, area from dozens to hundreds of was, was by the development of wire and cable and then to the conductive bus. They are at the new products, has become China's conductive aluminum alloy with high strength, large carrying capacity, long service life, wear resistance and easy processing characteristics. At present, more than 20 domestic provinces and cities, factory production of rare earth alloy wire

alloying

Rare earth reinforcement in the aluminum powder alloy, mainly fine grain strengthening, solid solution strengthening limited and rare earth compound second phase strengthening, etc. When not at the same time, for the amount of rare earths in rare earth aluminium alloy mainly exists in three forms: alpha (Al) solid solution in the matrix; Partial gathered in the grain boundary phase boundary, grain boundary and branches; Solid solution, or in the form of compounds in the compound. When rare earth content is low (less than 0.1%), rare earth mainly used two forms of distribution. The first form have the effect of the limited solid solution strengthening, the second type increases the resistance to deformation, promote the dislocation multiplication, the strength Calcium silicon. After joining the rare earths, the alloy as-cast organization, alloy grain size significantly reduced, could reduce the secondary dendrite spacing, rare earths and Al, Mg and Si element such as the formation of the intermetallic compound spherical and short rod distribution in grain boundaries or limits, distribution of a large number of dislocation in tissue. When the rare earth content is more than 0.1%, after a form began to dominate. At this time, rare earth with the other elements in the alloy begin to form many new phase containing rare earth elements; At the same time make change shape, size of the second phase, may make the second phase from a long strip shape into a short rod-shaped particles, such as, the size of the particles is also becoming more small, and scattered. Most containing rare earth elements in the second phase of the characteristics of the particles, the spheroidizing and refinement, this kind of change are reinforced aluminum alloy to some extent.

Rare earth can significantly reduce the inclusion quantity of two reasons

(1) the characteristics of rare earth oxides with high melting point, than the major, the proportion of about 2.5 times higher than pure aluminum powders. The greater the proportion of oxide, in the process of let stand, the more you will sink of inclusions, thus the remnants of the inclusions in aluminum liquid quantity the less;
(2) rare earth to join aluminium alloy liquid, liquid aluminum is smooth, does not like other refining agent boiling violently, secondary oxidation in the melting process, thus incorporated into the regenerative oxidation film (Al2O3) few in number. Deoxidization Sic Refractory of rare earth elements than deoxidizer Al, Mg, Ti, trace rare earth can make [O] strip to < 1 x 10-4%. Rare earth desulfurization ability is strong, can generate RES or RE2S3, products mainly depends on the activity of rare earth with sulfur or solubility. Rare earth elements in the fluid of the metal, also can react with O and S at the same time generate RE2O2S type sulfide. Rare earth elements can also with low melting point metal such As P, Sn, As elements combined, generate REP, RESn, REAs compounds. These rare earth compounds have the characteristics of high melting point, the proportion of light, when they are higher than the melting point of metal smelting temperature, can rise of slag. Their tiny particle becomes aluminum heterogeneous nucleation crystallization process, the removal of impurities in aluminum and its alloys. So, rare earth can make aluminum impurities redistribution, bulky compound glomeration, purification and grain boundary, improve the deformation, plastic processing of aluminum and its alloys.

Rare earth removal of impurities and on the influence of the inclusions

Distribution in aluminum and its alloy matrix and grain boundary compounds for all kinds of intermetallic compound and the oxide and aluminum oxide. The composition, morphology, distribution and quantity of these compounds on the performance of the aluminum and its alloys, especially the plastic processing and performance has a significant influence. Inclusion of aluminum powder and its alloy owner if Al2O3 etc. Nonmetal inclusion, its existence not only reduce the processing performance and mechanical properties of alloy, and worsen the casting performance. When pure aluminium (as-cast, variable form) after adding 0.2% of rare earth, the distribution of the original intracrystalline bulky blocks disappear, spherical rare earth phase formation, grain boundary strips and fragmental compounds decreased significantly, the point chain compound forming, plastic good uniform organization. And found that after adding 0.2% rare earth alloy, the original is distributed in the intracrystalline glomeration of rough patches, and in the uniform distribution of globular phase is formed on the substrate, while eliminating the boundary brittle fragmental and strip compounds, forming small point chain distribution of plastic compounds, and lined up along the deformation direction. To join before and after the rare earth Alumina Oxide and its alloy matrix, the grain boundary in the compound, intracrystalline bulky compounds and globular compounds such as phase composition were determined. Contrast found that after joining the rare earth, which makes the impurity in the aluminum and its alloys, such as iron and other elements, to high rare-earth poly globular phase, so that the final solidification grain boundary of impurity element is greatly reduced, purify grain boundary, the grain boundary in high-speed rail brittle phase reduction, grain boundary strength increased, the plastic improvement; And grain boundary distribution point chain compounds as low iron, the composition of rare earth phase, is close to the aluminum substrate of plastic compounds, particularly in the rare earth alloy spherical phases partial quantity is relatively pure aluminium cuhk, so its distribution in aluminum alloy grain boundary minimal, so the boundary of aluminum alloy is more thin, more pure than pure aluminium.

Rare earth is explained in rounding of aluminum and its alloys

Studies show that of Al - Si metamorphic process directly affects the bad effect of rare earths. Stability metamorphic organization is the key to reduce the loss of rare earth, and to prevent the rare earth together, in the rare earth evenly spread rapidly to the liquid Alumina Oxides; In order to obtain stable metamorphic organization, should as far as possible to improve metamorphic temperature, metamorphic strengthen let stand, after strictly grilled slag after refining, and as far as possible need not halogen element flux for refining and cover. Rare-earth has certain incubation period, must maintain a certain amount of time at high temperature, rare earth can maximize metamorphism.
Purification effect
Rare earths to gas and the impact on the rate of pinhole
Aluminum and its alloy in the casting process, a large amount of gas will dissolve in liquid aluminum, mainly hydrogen (about 85% of gas in liquid aluminum), followed by oxygen and nitrogen. Hydrogen source is mainly in charge of water vapor, aluminum ingots and leftover material of oil, water, and on the surface of the aluminium ingot aluminum "rust" - Al (OH) 3. Hydrogen is the main reason for the aluminum powders casting of pinhole, and significantly reduce the strength of the aluminum. All can in rare earth added to the aluminum and its alloy degassing effect. When less than 0.3% for the amount of rare earth, rare earth in addition to the obvious effect of hydrogen, reduce the amplitude of pinhole rate is the largest also. After more than 0.3% when the content of rare earth, rare earth content increases, the hydrogen content is slowed down. If Y, single rare earth La, when rare earth content more than 0.3%, the increase of the content of rare earth makes hydrogen content started to rise again, changes in the rate of pinhole has the same rule, but the change is more obvious. The author thinks that to hydrogen effect in order to Y > La > Re (mixed rare earth); From the content, a single rare earth content is less than 0.3%. Rare earth with oxygen, nitrogen can generate a kind of refractory compounds Re2O3 and ReN2. In the process of smelting, mostly in the form of slag elimination; At the same time, when temperature is less than 200 ℃, rare earth and fluorine, chlorine violent action can generate of rare earth and rare earth chloride, fluoride to remove fluorine and chlorine in aluminum. So, the rare earth in the aluminum alloy can be used as purifying agent.

The role of rare earth in aluminum and its alloy

Rare earth elements is very lively, extremely easily with gas (e.g. hydrogen), non-metallic (such as sulfur) and generate the corresponding stable compound metal effect. The atomic radius of rare earth calcium silicons is less than common metal, such as lead, magnesium, etc., in the solid solubility of these metals is extremely low, almost can't form a solid solution. In the rare earth elements added to the aluminum alloy can have the effect of micro alloying; In addition, it with gas such as hydrogen and many non-metallic strong affinity, can generate high melting point compounds, so it has certain than hydrogen, refining, purification effect; At the same time, the rare earth elements strong chemical activity, it can be selectively on has formed the grain interface adsorption, hinder the growth of the grain, with the result that grain refinement and qualitative change.
metamorphism
Modification Brown Corundums is to point to add a small amount of in metal and alloy or trace of inoculant, to change the alloy crystallization conditions, make its organization and performance improvement process. Metamorphic agent is also called the grain refining agent and nucleating agent. Typically, rare earth atomic radius. Because of rare earth elements is lively, it melt to fill easily in the liquid aluminum alloy phase surface defects, and reduces the surface tension of the old and the new two phase interface, make the crystal nucleus growth rate increased. At the same time it also can between grain and alloy liquid in the formation of surface active membrane, prevent generating of grain growth, thus refine the organization of the alloy. In addition, as an exotic crystal nucleus, aluminum and rare earth compounds in metal crystal formation, due to the large increase in number of crystal nucleus and thus refine the organization of the alloy. Rare earths in al-si alloy is mainly the metamorphism, make needle, lamellar eutectic silicon spherulitic, make less of the scale of the primary silicon. The stale ability is different, different rare earth La and Eu has strong metamorphism, and the mixture of rare earth and Ce only moderate ability of metamorphism. Lanthanide metamorphic ability has a close relationship with atomic radius, as the atomic radius from La to Er of 0.187 nm 0.175 nm, the metamorphic capacity decreases. All in atomic radius is less than 0.18 nm, metamorphism is reduced to the point of no practical significance. Different metamorphic ability of rare earth elements available critical cooling rate of deterioration (Vc), Vc is smaller, the bad effects, the more obvious; When V is smaller than that of Vc, any concentration of rare earth elements can cause alloy, this is one of the main difference between rare earth and other metamorphic agent.

Rare earth application in aluminium alloy

Rare earth is effective additives in metallurgical industry, rare earth metal has the very high chemical activity, low potential and special black silicon carbides shell structure, almost can react with all elements. Rare earth resources in China is very rich, complete varieties, good quality, wide distribution, mining and convenient. Has proven reserves of rare earths, of t, accounting for 80% of the world's reserves, the world in the first place. In recent years,
Rare earths in metallurgy, machinery, petrochemical industry, electronic, atomic energy, medical, agriculture, aviation and defense Brown Corundum and other fields has been widely used. Rare earth started relatively late in the application of aluminum and its alloys, abroad began in the 1930 s, China began in ShangShi 60 s, but develops very fast, especially in the role of aluminum and its alloys and applied research has achieved obvious effect. This is mainly concentrated in the silicon al-si casting alloy, aluminum and magnesium (zinc) deformation aluminium alloy, aluminium alloy wire and piston alloy, etc. The influence of rare earth on aluminium and its alloy regularity and mechanism research has made some progress.

Aluminum oxide cleaning liquid

The used motor shell is very difficult to clean
Oil pollution situation is more complex
May also with dirt and dust
Going to the Alumina Oxides layer is not black cannot use hydrochloric acid, can only use ultrasonic cleaner and cleaner
I come into contact with a similar situation
For your reference
1, automatic ultrasonic cleaning line
High pressure spraying and aluminum cleaner (removal of workpiece surface soil, and heavy dirt)
Ultrasonic aluminum cleaner (thoroughly remove the workpiece surface oil pollution)
Ultrasonic aluminum powder oxide cleaner (removal of oxide layer)
Rinse (if there is oil plus an ultrasonic aluminum cleaner process)
Rinse and drying
2, manual cleaning and ultrasonic oxidation layer
In an aluminum cleaner first
Artificial scrub (using aluminum cleaner, remove dust dirt oil dirties, instead of high pressure spray)
Ultrasonic cleaner to remove oxide aluminum oxide layer
Rinse (if there is oil plus a scrub)

Garnet evaluation of choose and buy

Assessment and the choose and buy of garnet in color, transparency, is based on the particle size. The standard requirement of gem grade garnet sand: transparency is good, bright color, particle size greater than 5 mm. Emerald green garnet is very popular in the international gem market, pure and flawless, color bright, glittering and translucent get rid of the emerald green garnet value is very high. Emerald chrome vanadium aluminum garnet (also known as sand fry stone) value is very high, good quality can be compared with emerald. Red and orange red garnet is also very precious, orange orange garnet (also called spessartine) price increases rapidly in recent years.
Garnet is one of the high-grade gem, including green gemstone belongs to the rare species. Variety is more, pure color, transparent purple tooth of the market. Its refractive index is high, strong luster, color diversity of beauty, is a popular gem varieties. Many countries in the world dental purple as the "January birthstone, symbol of loyalty, friendship, and chastity. Westerners believe that purple tooth wu has the save people's lives or magical effect; In the Middle East, purple tooth wu were selected as royal tribute.
Assessment and the choose and buy of garnet in color, transparency, is based on the particle size. The standard requirement of gem grade garnet: transparency is good, bright color, particle size greater than 5 mm. In the international gem market, pure and flawless, bright color, glittering and translucent get rid of the garnet value is very high. Emerald chrome vanadium buy brown fused alumina garnet highest value, high quality can be compared with emerald. Red, orange red garnet is also very valuable. Purple tooth wu is now one of the more common low-standard gems. Variety is more, pure color, transparent purple tooth of the market. Its refractive index is high, strong luster, color diversity of beauty, is a popular gem varieties. Many countries in the world dental purple as the "January birthstone, symbol of loyalty, friendship, and chastity. Westerners believe that purple tooth wu has the save people's lives or magical effect; In the Middle East, purple tooth wu were selected as royal tribute. Geological museum of China, with an orange red spessartine big crystal, weighing 1397 carats, which are found in xinjiang. By the national museum of natural history of the world's best a brown yellow transparent cinnamon stone grossular (iron), is a carving exquisite Christ's head, weighs 61.5 carat, is priceless.
Garnet imitation goods is few, very easily, respectively.
1, if the garnet color ultra bright transparent, if the price is very attractive, go easy.
2, the cotton impurities, garnet outside have black spots, ice crack very easily.
3, garnet heavier than individual crystal, measure under in your hands, if is lighter than powder, be careful.
4, garnet contrast is exquisite, appearance, feel is very slippery, it feels very comfortable oil feeling ~ not powder "glass".
5, garnet, strong luster, look have metal feeling that bright light have a hazy feeling, it is particularly obvious on the nib.

Brown fused alumina, alumina porcelain, high-frequency porcelain, what material is used for grinding the? And other?

Brown fused <a href="https://www.facebook.com/pages/White-fused-alumina/151832528325664">White fused alumina</a>is mainly used in: 1: abrasives 2:3: refractory sandblasting 4: emery wear-resisting floor 5: precision casting mould making.<br />Dongguan  widely suggested is a dedicated to promoting new environmental  protection polishing equipment, grinding materials, additives, such as  hundreds of kinds of product research and development of high and new  technology enterprise, the high frequency porcelain products used in  various types of high-<a href="http://www.hnhxgk.com/key-sic-refractory-240/">Sic Refractory</a>insulator,  porcelain dial section switch axis, porcelain bushing, resistance  matrix and containment shell electron yuan, device, it has high thermal  insulation, good chemical stability and good compressive strength  etc.Grinding stone is indispensable in the process of grinding and  polishing metal processing material. With centrifugal, vibration, eddy  current, rotary, box-type grinding machine. To metal burr, flash, scale,  rusty spot, inverted, rough grind cutting edges and corners

Fused silica refractory

Fused silica refractories and technical equipment for its manufacturing  process compared to other refractory industry is relatively simple, and  compare its performance and relative location, and the cost is low, and  it could get a lot of applications, since we started late in our  manufacturing processes and equipment Western countries is less than  perfect with industry manufacturers, compared with foreign refractory  Sic Refractoryindicators and the results of not less than the level of  similar products, but our products due to processing equipment is not  complete, in appearance, there is a large gap with foreign products,  select performance processing equipment, improve the appearance of the  product, and should be not only external beauty but also inner beauty so  that product quality to the next level.

Types of high alumina refractories

Ordinary Alumina Oxide bricks: the main mineral composition of alumina bricks mullite, corundum and glass phase. With products in the aluminum oxide content.Increases, mullite and corundum phases increases the number, a corresponding reduction in the glass phase, products increase as refractoriness and high temperature performance
Modified alumina bricks: including high load soft high alumina bricks, high alumina bricks micro-expansion, low creep high alumina bricks, high alumina brick phosphate-binding.

How much is the density of corundum?

Density is divided into two kinds of Brown Corundum is called, one corundum bulk density, particle density, the second is Brown Corundums.

Bulk density of 1.53 ~ 1.99g/cm3, abrasives and abrasive particle bulk density, particle size composition, species, particle shape and other factors are related, in general, coarse-grained than fine-grained abrasive abrasive bulk density, particle size of the abrasive mix Bulk density is greater than a single particle density.

Particle density of 3.95 ~ 4.0/cm3, the silicon carbide abrasive particle density refers to the unit volume (excluding the volume of open porosity) contained within the abrasive mass

About emery abrasive categories and methods of use

Metal cutting and abrasive surfaces Shuhei process of the main material . In actual production , the commonly used abrasives are synthetic diamond , corundum , silicon carbide, diatomaceous earth, pumice, quartz sand and so on.
Artificial corundum - with high hardness and toughness small ( compared to other abrasives ) is mainly used for rough grinding and polishing low strength metals ( such as pig iron , brass, bronze, etc. ) polished .
Corundum - There are two man-made and natural . The bauxite corundum Al2O3 content , the more the higher the hardness . Corundum is the use of better materials coarse grinding wheel , than artificial corundum toughness . Corundum particles are multi-faceted , sharp edges of particles than artificial corundum was blunt sharp edges . For polishing and tough and has a large breaking strength metals such as hardened steel , malleable iron, manganese bronze.
Emery - with medium hardness and excellent toughness , applicable to all metal polish .
Diatomaceous earth - with less sharp cutting surface and excellent toughness , repairable flat metal surface scratches and scratches and other defects. It is generic , polishing materials .
Quartz sand - particles with medium hardness , it is not a sharp cutting surface , and its toughness is also very good , the universal grinding and polishing materials .
Pumice - its hardness is poor , but also more crunchy , suitable grinding, polishing wood, leather , rubber, plastic and glass.
According to the above kinds of abrasive nature , summed up in the grinding hard metal products , to use artificial corundum , corundum or emery, then fine emery , pumice, finely ground quartz powder . The polished softer metal products , generally with diatomaceous earth and pumice .

Special diamond polishing technology products and Scope

Now more and more extensive use of polished sand in many areas consistent with the extensive use has been received , so that the scope of these products is very wide, polished sand below introduce you to the basic concepts and polishing abrasives scope .
Polishing sand profile:
High quality silicon carbide abrasive polishing sand as raw materials using modern new unique technology is refined . Abrasive polishing abrasives short time , high efficiency, good benefits , and low prices . The product hardness, high toughness, good self-sharpening , sand consumption is low and can recycle and reuse , grinding pieces of finish is good ; and chemical stability , wear resistance, acid and alkali. The abrasive shell-shaped fracture , sharp corners , constantly smashing step in the formation of new edges and the side edge , making it superior to other abrasive grinding capacity . In particular it has a high hardness, specific gravity , chemical stability and its unique advantages to become self-sharpening , polishing process with abrasive sand is preferred ; while the workpiece is polished rust cleaning , polishing the ideal material.
Polishing abrasives Scope:
Mainly used in the stainless steel surface decontamination, in addition to welding slag and matte effect , iron workpiece to rust, decontamination , descaling , increasing the coating , the coating adhesion, aluminum workpiece descaling, surface hardening , light decoration role of oxidized copper workpiece to Pia light effects , frosted glass crystal , engraved pattern , plastic products ( hardwood products ) matte effect , denim and other special fabrics , plush processing and effect patterns, according to user technical process conditions according to user requirements , customized for the user a variety of polishing abrasives such as sand with emery ; automobile factories, shipyards rust surface polishing with a polishing sand.

Black silicon carbide, and advantages of the use of performance

black silicon carbide is a very hard material intensity, the product mainly by petroleum coke, quartz sand and silica materials such as smelting, and is widely used in sandblasting, grinding and polishing, carborundum wearable Floor, Carborundum Abrasives, precision casting mold shell production.
Black Silicon Carbide Uses:
1, the mold surface of the grain,
2, very clean hard surfaces such as: tungsten carbide workpiece
3, with a large sand sculpture in depth, such as stone carving, etc.
4, thin and brittle workpiece sandblasting, cutting
Black silicon carbide Performance and advantages:
Black silicon carbide with anti-crushing ability, corrosion resistance, low cost, high temperature oxidation resistance, hardness, toughness, fitness and other characteristics.
Black silicon carbide is suitable for dry and wet two sandblasting abrasive most affordable, especially for the more rough surface for processing, while the treated surface also requested finer occasions.

Corundum content of impurities on the properties of

Corundum abrasives in one of many, was able to buy the product is very good, as long as it is attributed to good performance of the product, so that customers are able to favor such a product, but sometimes also corundum There will be miserable impurities, thus affecting its performance.
There are two ways of making corundum, most notably through the method of production of fused corundum, the production process is such high quality bauxite, no trouble coal, iron as the main raw material, through the use of electric arc furnaces in 2200 ℃ above high temperature purification, cleaning, crystallization, sorting, crushing, magnetic separation, screening and other means of processing into various particle size of the product.
The role of corundum quality will affect its effect, how to judge the quality of corundum or bad yet. Corundum in the production process may contain impurities, the main impurities are SiO2, Fe2O3, TiO2, fewer impurities, the higher the quality corundum. Determine the content of impurities in corundum corundum be judged good or bad a way. Besides the content of Al2O3 corundum is also directly explain how good or bad the quality corundum.
Recent years due to rising prices, electricity prices increase the production of corundum increasing pressure, fierce competition in the market there are so many unscrupulous businessmen led to the production of corundum quality is getting worse. Corundum as a wear-resistant materials in recent years, product quality often unstable, chalking, cracking phenomenon of frequent occurrence. So in the purchase process corundum determine its quality is very important.
Corundum can be used as refractory if containing impurities will affect its fire-resistant properties. Some refractories fusible material impurities, and some have a very high melting point in itself, but coexist with the main component, they can produce a fusible material. Therefore, the presence of impurities is often the main ingredient from strong fluxing action. Fluxing action, although the material is liquid phase sintering help, but there is material to resist high temperature serious harm.

Describes how to strengthen corundum production environment

Brown Corundum in the production process have a good production environment , so that we can produce a good product, following a brief look at strengthening the production environment corundum What?

Conventional aluminum oxide abrasive machining process of exercise and ordinary have dust pollution, water pollution, air pollution and noise pollution, echoing national calls , protect the environment, the current management of these enterprises has begun to pollute . Dust Disposal : You can use active anti- pulse bag and cartridge filter to dispose of machining processes occurring dust pollution of the environment . This method is still present the best selection of the dust disposal .
Water Pollution Treatment: Alignment washing Alumina Abrasive water pollution , we first use of zero-emission to dispose of the water cycle ; pickling abrasive water pollution , we deal with a high temperature to replace after pickling pickling process completely dispose of water pollution , after a multi- purified water , cleaning water can be seen , the water, the precipitate is filtered in the sewage tank .

Do you know the role of powder characteristics is

White fused alumina powder as raw material, made ​​of high-temperature melting. White, slightly higher hardness than corundum, lower toughness. With its manufacture of abrasive for high carbon steel, high speed steel and hardened steel grinding. Used as a polishing material, but also for precision sand casting, coating materials, chemical catalyst carrier, precision wear characteristics.
Green silicon carbide with quartz sand and petroleum coke as raw materials, high temperature melting, green translucent crystals, high hardness, cutting ability, suitable for machining hard and brittle materials, such as cemented carbide, high speed steel, and optical glass, ceramics, agate and other non-metallic heating elements, heat originals.

 

What is processing corundum

Corundum is generally polygonal shape diamond , so the colors are white , then in today's society, many people do not know what is corundum , but do not know what effect it has , generally used in the wrong ?
Corundum Scope:
Etching processing: jade, crystal , agate, semi-precious stones , stamps, ornamental stones , antiques, marble gravestone, ceramic, wood , bamboo , etc. etched art .
Pretreatment processing: PTFE (TEFLON), PU, ??rubber, plastic coated , rubber drum (ROLLER), electroplating, metal spray , titanium , etc. Before treatment, the increase in surface adhesion .
Beautification processing: various gold , K gold jewelry, precious metal or of extinction matte , crystal , glass, corrugated , acrylic, and other non-metallic matte processing and enables the workpiece surface into a metallic luster.
Surface processing: metal oxide layer, carbide black , metallic or non-metallic surface dirt rust removal , such as gravity die casting, rubber mold of the oxide or remove agents from the shape , ceramic surface black spots , uranium -color removal , painting rebirth.
Flash processing: bakelite , plastic, zinc, Alumina Refractory,aluminum die-casting products , electronic parts , core , etc. burr removal .
Stress relief processing: aerospace, defense, precision industrial Parts , rust, paint extinction , renovation etc. stress relieving processing.

Common types of abrasive

Need to use the mold with abrasive, abrasive and share with everyone today, the main species, which mainly include mainly corundum, white corundum, silicon carbide and green silicon carbide.
Corundum high toughness, suitable for grinding carbon steel, alloy steel, malleable iron and hard bronze high tensile strength of the material. Corundum has a higher hardness than corundum, cutting performance is better, for hardened steel, high carbon steel, high speed tool materials such as grinding processes.
Black silicon carbide, high hardness, brittle and sharp, suitable for grinding, cutting, low tensile strength of the material, such as: cast iron, glass, ceramics, stone, refractory material and so on.
Darker green silicon carbide high purity silicon silicide. Suitable for grinding carbide, optical glass, precious stones, agate and other hard and brittle materials.
Granularity:
The choice of abrasive particle size depends on the surface of the workpiece machining accuracy and productivity requirements. Coarse-grained and medium-grained abrasive for roughing and semi-finishing, and fine-grained abrasive, it applies to finishing and super finishing. Physical and mechanical properties are grinding department also factors that determine particle size, low hardness, ductility and toughness of the material is appropriate to coarse-grained abrasive machining, high hardness brittle materials appropriate to fine-grained abrasive.
Organization:
Organization refers to the abrasive grinding composition of the abrasive, bond and porosity volume ratio between the three. Less abrasive, large porosity called loose tissue, otherwise tightly organized.
Tightly organized abrasive, should be used for grinding, profile grinding and processing remain small while the surface finish of the workpiece.
Medium organizations are widely used in the general allowance abrasive grinding work piece.
Loose abrasive for flat organization, such as the inner circle of a large contact surface of the grinding and grinding expansion sensitive soft material of the workpiece and the workpiece.
Hardness:
Abrasive abrasive surface is fixed to the strength of the binding agent. Or under external force, the degree of difficulty shedding, known abrasive hardness.

Calcined corundum abrasives advantages

1, the elimination of the aluminum oxide abrasive abnormal expansion: As in the smelting process of fused alumina abrasive containing low-cost titanium (Ti 0, TiO) and titanium carbide, titanium nitride (Tic, TiN), their 1000% to 900% of a calcined in an oxidizing atmosphere, it will further oxidation, the volume increases accordingly, the volume change of the abrasive itself beyond its normal expansion, the expansion is abnormal.
Abnormal expansion of the abrasive, the ceramic corundum grinding wheel causes the firing, the surface mesh cracks, resulting in a large waste, and the use of calcined aluminum oxide abrasive to eliminate anomalous expansion of the most effective means.
2, to improve the toughness of the aluminum oxide abrasive and grinding performance: The study found, this is due to the abrasive in the calcination process, the first corundum crystalline solid melting at the TI3 + is oxidized and cause contraction of the lattice, thereby increasing the abrasive resistance compressive strength, followed by calcination in the granulation process will make the internal stress caused.
Thus, after calcination produces a variety of abrasive grinding tools, not only durable and sharp increases abrasive grinding performance.

Quartz powder production technology introduced

According to the final use of the product needs to determine the appropriate and suitable purity quartz particulate material , you can make quartz powder ( silica ) grinding .
Basically, the abrasive quartz powder, a wet and dry in two ways , namely wet blended with a certain proportion of the raw materials in water ( if the product is of high purity , deionized water can be used ) , in a grinding machine , then use the water classification ( sub granularity ) , drying process .
This method had previously been used as a wider range of silica processing methods , but because of its need to consume a lot of water , emit large quantities of contaminated water and waste a lot of heat drying , water classification accuracy is relatively low granularity , use is also dwindling .
Currently, only a small part of the requirements of the electronics industry requires a special use of such products.
Dry grinding currently used more widely , and there is more and more increasing trend . The basic approach is to choose a suitable grinding media for grinding and sieving or air classification granularity ( sub granularity ) . In this way , environmental economy , and the exact size air classification , the only shortcoming is that the composition of the wear of grinding media , the product will be a small increase in its ingredients. So choose a highly efficient grinding effect , low wear and, as a small amount of impurities contained in the product acceptable for most industries grinding media are particularly important .
Currently, a large industry proved corundum alumina ( main component of 95% Al2O3, other minor components mainly SiO2) is the most suitable grinding media . Various industries, basically acceptable use of alumina corundum abrasive silica products.
Silicon micro- grinding equipment selection , there are a variety of grinding equipment, a rod mill , cone mill, Raymond machine, but because of its inevitably bring products in the processing of a large number of Fe2O3 content , it can only for the production of building materials, refractory and other industries low demand quartz powder .
Electronics, chemicals , paint and other industries generally use the ball mill, jet mill , but it can be a huge airflow wear suitable only for 2500 mesh products with fine , so far the most widely used is the ball . May be wet , but also for dry -type , for the continuous production , but also for the production batches . Wherein the abrasive media can also choose to select the previously mentioned alumina corundum, quartz can also choose to block itself can also be used with both .
It can also be controlled with air classifier granularity control the final product , is currently the most widely used in the production of silica as a reasonable solution .

The main function of corundum

(1) Due to high temperature, corrosion resistance, high strength and other properties, it poured with steel sliding gate, smelting rare metals, special alloys, ceramics, blast furnace lining (walls and tubes); chemical containers, spark plugs, thermal oxidation resistant coating.
(2) Because of hardness, wear resistance, high strength characteristics, in chemical systems, used a variety of responses utensils and pipes, chemical pump parts; doing mechanical parts, various molds, such as wire drawing dies, extrusion die nozzle pencil, etc.; make tools, dies abrasive, bulletproof material, human joints, sealing ring mold.
(3) corundum insulation materials, such as lightweight corundum bricks, corundum hollow spheres and fiber products, widely used in various high-temperature kiln furnace wall and roof, both high temperature insulation. Size sand corundum corundum block by artificial selection, using the roll, milling, processing Barmac other equipment, particle size by the F8-F325. Mainly used for polishing, grinding, industrial grinding, etc., can also according to customer requirements for washing, pickling and other processing methods to meet the different needs of customers.

Silica fume on the strength of high performance concrete

Although the application of pure cement can be made up to 100 MPa compressive strength of HPC, but will be much easier when using silica fume. For the preparation of the concrete strength exceeds 100 MPa, the use of silica fume is almost indispensable. Silica fume in concrete filler material and volcanic ash from the same material. Using silica fume, greatly reducing the hydration slurry pore size, pore size distribution improved, so that strength, permeability decreases.
For example, the study results show that (CEB2FIP1988), in order to obtain 70 MPa concrete strength, the application of pure cement needs water-cement ratio 0.35, and when plus 8% silica fume, the water-cement ratio can be 0.50. Since silica particles are very fine, they can occur within a few hours early pozzolanic reaction. According to Carette and Malhotra 1992) reports, the contribution of silica fume concrete strength mainly in the 28d before. So, the long-term strength of growth, generally considered as pure silica fume concrete cement concrete or fly ash concrete. Almad (1994) cited the development of silica fume on the NSC strength test results show that silica fume dosage increases the relative intensity of the early development of such reduction, Sandvik 1992 at 65 MPa concrete were also found in this phenomenon.
However, although the same water-cement ratio relative strength of silica fume concrete in the early development of slower than pure cement concrete, such as silica fume added strength greatly increased, the absolute strength of silica fume concrete is higher than that of pure cement concrete. On the other hand, experience has shown, HPC early strength development faster than the NSC, although HPC setting time may be slightly delayed hydration after its condensation due superplasticizer and silica fume greatly accelerated. The result is usually very fast strength development after condensation.
For some air drying or curing of low water-cement ratio of silicon carbide silica fume concrete specimens with compressive strength retraction reports (De Larrard and Aiticin 1993). This reduction in strength usually occurs after the age of 90 d, is generally considered by an internal self-drying and drying cracks caused. However, many other researchers in laboratory and field studies have shown that, HPC's late strength is not reduced. For example, from 6 different HPC obtained in three months to three years, all drill core samples of test results show that the intensity is growing. Of course, compared with the NSC, HPC's long-term growth potential of smaller intensity.

Black corundum corundum smelting method and the same

(1) A corundum
Corundum is bauxite, coal and iron as raw material in electric arc furnace at high temperature smelting. In the smelting process, the carbon anthracite in the silica alumina, iron oxide and titanium oxide is reduced to metallic impurities, the alloy of these metals taken together, due to its large specific gravity than the molten corundum to the bottom of settlement and corundum melt-liquid separation. Only a small amount of impurity inclusions in the corundum melting fast.
The main ingredients of mineral corundum corundum physics, trigonal system, a small amount of mineral impurities are: calcium silicate, calcium plagioclase, mullite (also known as mullite), titanium compounds, vitreous, and a small amount of iron alloy.
Corundum anti-crushing ability, anti-oxidation, corrosion resistance, good chemical stability, which is a widely used abrasive. Suitable for grinding high tensile strength of the metal materials, such as ordinary carbon steel, hard bronze, alloy steel grinding and grinding, thread and gear grinding, white fused alumina can be used for precision casting and high-grade refractory.
(2) black corundum BA
Black corundum corundum smelting methods and the same is Sanshui bauxite as raw material, add a small amount of reducing agent is made by smelting, its power consumption is about two-thirds of corundum. Black, the main chemical components: Al2O3 not less than 77%, SiO2 content of 10 ~ 12%, Fe2O3 content is 7 ~ 10%, TiO2 is about 3%, the proportion of not less than 3.61.
Black corundum with good self-sharpening, grinding, less heat, better finish machined parts for the bottom part before plating polished, aluminum and stainless steel polishing, can also be used to polish optical glass, processed timber. Due to its hydrophilic, can be used in the manufacture of sandpaper, emery cloth and resin abrasive, but also can be used for polishing paste and polishing powder. Black corundum due to iron content is high, and therefore should not be used in the manufacture of ceramic abrasive.
(3) White corundum WA
White fused alumina powder as raw materials in industry, in the arc by melting temperatures above 2000 degrees and then cooled steel. Aluminum oxide (Al2O3) content of 98%, and a small amount of iron oxide, silicon oxide and other ingredients, white.
Harder than corundum corundum, grit easily broken, sharp edges and corners, good cutting, grinding, heat a small and so on. For hard materials, heat-sensitive strong steel grinding. Such as hardened steel. High carbon steel, general high speed steel, alloy steel grinding. Mainly used for tools, cutting tools, dies, gears, threads, thin-walled parts grinding and profile grinding.

Green foreign polishing process using silicon carbide powder

Polishing process includes: Calibrating grinding, rough grinding, the grinding, fine grinding, polishing, edging and inverted corners and other processes. Abrasives and Abrasive used: Calibrating the above steps except use emery grinding, the rest are made of Green silicon carbide powder fineness ocean. Polishing is required for the cooling flush face to face away produce a lot of heat to prevent the products burst. After polishing needed for drying, waxing or other surface coatings to enhance its dirt capacity, improve the gloss, the current process is mainly used for polishing finishing ceramic tiles, and has developed a fully automatic polishing machine. The flexible abrasive polishing tools and polishing media particles or other modification of the surface of the workpiece processing.
Polishing can not improve the dimensional accuracy of the workpiece or geometric shape accuracy, but to obtain a smooth surface or specular gloss for the purpose, sometimes to eliminate gloss (extinction). Usually as a polishing buff polishing tool. Buff general use multi canvas, felt or leather crafted stacked on both sides with a metal circular plate clamped its rim coated abrasives and grease, etc. from the powder mixture evenly polish. Uniform fine polishing using material degreased thin wood or a special felts, its trajectory uniform dense mesh, the surface roughness after polishing is less than Ra0.01 microns, the enlarged 40 times under the microscope than any surface defects.

About corundum What is the main component and classification

Refers to the industrial alumina white fused alumina powder as raw material in the arc melting temperatures above 2000 degrees through steel. Corundum main chemical ingredient is AL2O3, its content in a 98.65% -99.37%, and the other a small amount of Fe, Si, Ti and so on. Corundum for the manufacture of ceramic, resin bonded abrasives and grinding, polishing, sandblasting, precision casting, etc., can also be used to manufacture advanced refractories.
Corundum behalf # "WA" on internationally accepted standards, national standards, most for export, there is a certain amount of supply domestic users.
Sandblasting grade corundum is divided into:
16 # 46 # 60 # 80 # 100 # 120 # 150 # 180 # 200 # 220 # 280 #
Particle size in accordance with international standards and national standards of production, processing granularity according to user requirements. Universal size # is F4 ~ F320, its chemical composition varies depending on the particle size. Prominent feature is the small crystal size impact resistance, due to a self-processing mill crushed particles are mostly spherical particles, dry surface cleaning, easy binding agent combination. Year the company provides silicon carbide, white fused alumina, corundum powder, green silicon carbide powder and sand grain size.

Silicon carbide in the three fields of application

Silicon carbide is also called moissanite, silicon carbide products can be divided into many categories, depending on the use of the environment, divided into different categories.
A general use to mechanically more. For example, using the mechanical seal, it can be called a silicon carbide seal ring, can be divided into static ring, ring, flat ring. Can also according to customer's special requirements, produce a variety of shapes silicon carbide products, such as silicon carbide shaped pieces, silicon carbide plates, carbide ring.
2 of one of silicon carbide SiC article has a high hardness, high corrosion resistance and high temperature strength characteristics, which makes silicon carbide has been widely used.
3 In the application of the sealing ring: SiC good chemical resistance, high strength, high hardness, wear resistance, low coefficient of friction and high temperature, so it is an ideal material for manufacturing sealing ring. It is paired with the graphite material composition, the friction coefficient smaller than that of alumina ceramic and carbide, which can be used for high PV values, in particular transport acid and alkali used in the working conditions. I produced the SIC-1-type silicon carbide Sintered products, with high density, high hardness, producing large quantities, can produce complex shapes products, suitable for use in high-performance seals, especially high PV value and resistant to acid and alkali conditions. And I produced the SIC-3-type silicon carbide ceramics containing graphite, silicon carbide material. Since the silicon carbide substrate contains a large number of fine graphite particles dispersed, when paired with other materials, the friction coefficient is very small, has good self-lubricating properties, especially for the production of dry gas seals or seal friction condition the use, so that the service life of the seal and the reliability improved.
SiC refractory Information superior function, as we all know already, has been widely used. Currently, high-performance silicon carbide refractory data is still in the research and development period, the outstanding features of silicon carbide from the forward, lower costs intentions to leave, with plenty of information to grasp the composition, microstructure and functional link between is produced to ensure future , followed by discussion deepening will gradually expand its use of the field, the market is extremely broad prospects.

Classification and the use of a variety of abrasive range

Abrasive grinding material is used, the general classification is now common abrasives, superhard abrasive types; ordinary abrasive including corundum (corundum, corundum, etc.), and its main chemical composition Al2O3 (aluminum oxide) , silicon carbide (black silicon carbide, green silicon carbide), and its main chemical components of SiC (silicon carbide). They are corundum hardness, microhardness 2000-2200 kgf / mm 2; corundum, microhardness 2200-2300 kgf / mm 2; black silicon carbide, microhardness 3100-3300 kgf / mm 2 ; green silicon carbide, microhardness 3200-3400 kgf / mm 2; grain size from 4 # - powder W0.5 (or finer), the hardness in the order that we can sort out the processing of granite is green silicon carbide, black carbonized silicon processing marble is corundum (soft), black, green silicon carbide (hard).The cost from the material in order to see the green silicon carbide, black silicon carbide, corundum, abrasives can be made around these, inorganic abrasive tool including magnesite, ceramics, etc.; organic grinding tools, including phenolic, unsaturated resins, and epoxy, etc. (This also includes emery cloth sandpaper), which constitute the common abrasive grinding tools, grinding tools.Superabrasive diamond abrasive belongs, and its processing history is a relatively long, but as more use is the last three decades a large number of industrial production, and its hardness 8000-10000 kgf / mm 2; hardness is the highest , processed materials are micro-cutting mechanism, so it is the preferred cutting tool, in recent years, there is a massive increase in the yield and reduction of industrial costs, high processing efficiency, (which is 5 times more than normal), the processing effect (may demanding material for polishing), and thus, it is a widely used.Diamond grinding tools are metal, resin, ceramics, etc. This is the type of binding agent according to the classification, metal grinding instruments mainly include iron-based, copper-based, these types of cobalt, it determine the different types of materials processing costs, as grinding tools, from the most coarse particle size (20 #), often to the fine grain size up to 400 # for use; which is characterized by long life, but the cost will be higher.Resin grinding tools, due to the production costs are relatively low, the application should be relatively more, it is now also used for rough grinding to polishing, grinding and polishing in the fine-grained aspects is its greatest advantage; ceramic diamond grinding tools are recent was the fastest growing tool, its processing performance in metalworking take long, to avoid resin processing short, is technically a good advantage, but because of cost reasons, have not seen used in stone renovation.

 

Green silicon carbide on the use and what are the characteristics

Green silicon carbide is quartz sand and coke for raw materials as a good thermal conductivity, high hardness of man-made materials. Green silicon carbide, white fused alumina even at high temperatures also have high strength, the elastic modulus when the temperature reaches 1600 ℃, began to decay. At a temperature of 2815 ° C begin to separate, but it does not melt at atmospheric pressure. Green silicon carbide suitable for use as super refractories, is also widely used for grinding areas.
Use
For 3-12 inch monocrystalline silicon, polycrystalline silicon, GaAs, quartz crystal wire cutting. Solar photovoltaic industry, the semiconductor industry, piezoelectric crystal engineering of industrial processing materials.
Feature
1, high-purity, large crystal silicon carbide material, the cutting of silicon carbide powder to ensure excellent cutting performance and stability of the physical condition.
2, plot size and shape of such a front edge, to ensure cutting edge material as silicon carbide powder balanced self-sharpening to ensure the material being cut TTV is minimized.
3, the particle size distribution is narrow and uniform.
4, a high thermal shock resistance and load softening temperature, which ensures that the cutting load of the small coefficient of linear expansion, thus ensuring the stability of the cutting; cutting machines and able to have a good adaptation of.
5, the surface is specially treated, powder with a large specific surface area and clean appearance, and polyethylene glycol coolant has good suitability.

 

95 superhard materials in the field of polycrystalline diamond prospects

Polycrystalline diamond (collectively, polycrystalline diamond), is composed of many high-quality diamond powder at elevated temperature and pressure with (or without) the additive sintering conditions.
Synthetic polycrystalline diamond has the following characteristics because of its vitality shows: (1) crystal was disordered arrangement, and thus uniform hardness, non-directional; (2) has a high strength, especially impact strength and wear sex; (3) can be made into a specific shape; (4) can predict product design or performance characteristics necessary to give the product in order to adapt it for specific purposes.
Once you can replace other industrial diamond products, then you can get a huge market efficiency, which is a new development area of ??polycrystalline diamond. Previously, in oil well drilling, only two percent is the application of the cutting blade, tungsten carbide tips and the rest are occupied cone bit.
Now, the machinery industry, the tool commonly used material is high-speed steel, carbide, ceramics. These tools are made of a material difficult to effectively cutting hard, wear-resistant material difficult to machine.
Practice has proved that high cutting efficiency machining difficult materials ideal diamond tool should have as high hardness and wear resistance, CBN or ceramic as good thermal stability and chemical inertness, carbide as high strength and impact resistance, but even in the future can not find a material having all these desirable properties. Seen in this light, the development of a better tool materials the most promising approach is the combination of several known tool material to form a complex superhard material, so that it has a variety of excellent performance. U.S. GECo scientists back in the early 70s began to explore and research this composite material, they successfully developed PDC (Compax) and cubic boron nitride composite sheet (Compact), these two materials in the machining tool applications will be substantial growth, its fastest growing.
Drawing dies - drawing non-ferrous metals such as copper, zinc, nickel copper, aluminum, gold, etc., as well as hard-wire such as tungsten, molybdenum is better, especially drawing copper wire better. A drawing die before grinding can be drawn in 7000 t copper, equivalent carbide die 300 to 1,000 times, or natural diamond die 5 to 10 times.
Currently polycrystalline diamond drawing dies can be brushed diameter range of 8 to 0.1um. Because precision drilling technology can control a variety of profiled wires. As fine and ultrafine grain products emerge, polycrystalline can be used for drawing dies, but also for the finished mold.
Petroleum Geology Drilling - began in 1973, has had three series of polycrystalline diamond petroleum and geological drill mass production and application. GECo that: special geological drilling polycrystalline diamond - Geoset is synthetic diamond drilling applications in major developments.
Twist drill - the 1980s, the use of diamond drill holes on the extension to the general. One is the twist drill, drill blade inlaid with roof or gable-shaped sandwich formed PDC used in stone, concrete and other non-metallic materials, non-ferrous metals or alloys punch, is gaining popularity in the electronics industry.
Polycrystalline diamond mention the technical development of performance under the following aspects:
(1) the appearance of large polymer chips;
(2) Thermal Stability Product claim series;
(3) continue to refine the grain;
(4) the shape of structural diversification.

Three refractory materials

1) an acidic refractory silicon oxide as the main component, commonly used silica and clay. Silica is more than 93% silicon oxide-containing siliceous products, the raw materials used are silica, silica and other waste, and its acid resistance slag erosion ability, load softening temperature is high, the volume does not shrink after repeated firing, and even a slight swelling; but its vulnerability to erosion of basic slag, thermal shock resistance is poor.
2) neutral alumina refractory oxide, chromium oxide or carbon as a main component. Containing more than 95% of corundum alumina article is a wider use of high quality refractory material. Chromium oxide as the main component of chromium slag bricks for good corrosion resistance, thermal shock resistance, but poor heat load deformation temperature is lower.
3) alkaline refractory magnesium oxide, calcium oxide as the main component, is commonly used magnesia bricks. MgO containing 80% to 85% of the brick, the basic slag and iron slag has good resistance, high refractoriness than clay and silica.