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.