The graphite sintering mould used in powder sintering industry began in the early 70s, accompanied by geological exploration, coal exploration and mining, oil exploration and drilling, highway cutting, especially the rapid development of granite and marble mining and cutting industry, the demand of a substantial amount of diamond alloy material and hard alloy materials the demand for graphite sintering mould increased which is matched with the increases.

　　A wide variety of graphite sintering mould applications which used in powder metallurgy industry are from man-made diamond manufacturing industry.

　　The graphite sintering mould for diamond tools is mainly used in the two fields of building materials and exploration.

　　The graphite sintering mould used for diamond saw blade is mainly in the production of cutting marble, highway, ceramic tile and so on. It has the high demand of the physical and chemical technology properties of sintering mould. The dimensional tolerances of the machining parts are also very strict. The main products: sintering diamond cutter head combination graphite mould, sintering diamond saw blade graphite mould, diamond core drill with sintering graphite mould, diamond grinding wheel with sintered graphite mould, diamond wire saw sintered graphite mould used in petroleum drilling clay mold, gage ring and nozzle rod, sintering mold, diamond saw blade diamond grinding sintering mould, sintering diamond drilling tool with graphite mould.

　　The characteristics of the raw material of the graphite sintering mould: high temperature resistance, high oxidation resistance and high mechanical strength.

　　Our company has several imported high precision CNC machining equipments, and a group of more than 10 years of experience elites in the management, we collect the set design, development and manufacturing in one and can design new products to customers efficiently, provide the best solutions.

　　All vanadium redox flow battery (VRB battery, VRB) is a new type of green environmental protection battery, has the advantages of high efficiency, long service life, safe and reliable, can be used as a large energy storage device, the wind, hydro, solar and other unstable energy into electrical energy storage to be used as a backup power supply has a wide application prospect.

　　The hydrophilic and electrochemical activity of PAN based (PAN) graphite felt is poor and the graphite felt needs to be modified to be better used in vanadium battery. In order to improve the electrochemical activity of graphite felt, the two cerium oxide was modified on graphite felt by ethanol solution method and sol gel method. Two cerium oxide has the capability of storing and releasing oxygen and the diffusion capacity of fast oxygen vacancies, which is the most active catalyst in rare earth oxides.

　　Modified graphite felt, in the battery testing of the highest coulomb efficiency can reach 95%, energy efficiency is also close to 90%.Surface deposition method on the surface of graphite felt with catalytic activity of metal, is another kind of modified graphite felt. On the surface of graphite felt were introduced into manganese, cobalt and nickel three metals, and physical and electrochemical properties test of modified graphite felt. The results showed that the modified surface of graphite fiber functional changes, wettability of graphite felt, to improve its electrochemical activity. Battery test results show that the coulomb efficiency can reach 90%.

　　Graphite felt is a great ratio of carbon fiber surface area, can provide a larger electrochemical reaction for the electrochemical reaction, while the graphite felt has strong oxidation and corrosion resistance, and in addition to the conductive properties of itself, because the graphite felt electrode can be compressed, as battery assembly, contact resistance and bipolar in the small, compared with the metal electrode, the cost is relatively low, is a kind of ideal electrode material.

　　According to the quality requirements of products, the selection of raw materials and process conditions, the cathode carbon blocks in China are divided into 3 categories: common cathode carbon block, semi graphite carbon block and graphite carbon block. Ordinary cathode carbon block with 1250 to 1350 degrees Celsius calcined anthracite as the main raw material. Semi graphite carbon block according to the production process is divided into two different.

　　Which is a kind of high quality high temperature calcined anthracite or graphite fragments more even with all the bits of graphite as aggregate, green products after forming only after calcination (calcination temperature less than 1200 DEG C) is no longer in the graphite furnace heat treatment, the carbon block called semi graphite carbon block.

　　Another with more easily to the graphite of the coke for aggregate, raw material after baking and then enter the graphite furnace in 1800 to 2000 degrees Celsius temperature for heat treatment, this kind of carbon block called semi graphite (chemical) carbon block. The strength and hardness of the former is higher, and the conductivity of the latter is better. Graphite carbon block, in order to ease the graphite coke as raw material, the temperature of its graphite processing should reach about 2500.

　　The difference between the semi - graphite carbon block and the graphite carbon block lies in the degree of the ordered arrangement of the products, which is different from the degree of the degree of. The size of the product can be used to indicate the extent of the degree of graphite. The crystal lattice of the graphite carbon block is basically in a state of orderly arrangement, and the resistivity is less than 15 mu m; the degree of the semi graphite carbon block is low or only partially, and the resistivity is 15 to 45 m. In the process, the heat treatment temperature, the heat treatment of the semi graphite carbon block is about 2000 degrees Celsius, and the temperature of the graphite carbon block is 2800 to 2500 degrees Celsius. Common cathode carbon block, the resistivity of 50 ~ 60 mu m. Graphite cathode carbon block China has not been applied.

　　The expandable graphite was first discovered by the German scientist Shafautl when he immersed the graphite into concentrated sulfuric acid and nitric acid in 1841. But until the year of 1963, The Union Carbide Company in the United States first applied the patent of preparation of sealing material by the expansion graphite, and it was real used in the industrial production in the beginning of 1968 . Later, Countries in the world have launched the expansion of graphite research and development, and get serious scientific research and results, so in the current , the expansion graphite has become a kind of very important function of graphite materials.

　　The expandable graphite can be rapid expansion, expansion ratio of up to several tens to hundreds of even thousands of times under high temperature heating , the apparent volume of expanded graphite was 250 ~ 300mL/g or more, the graphite after expansion is wormlike, its size between a few tenths of millimeters to a few millimeters, with a large number of unique network like porous structure in the interior, called expanded graphite or graphite worm, the expanded graphite has many special properties.

　　The expandable graphite can be used in iron and steel, metallurgy, petroleum, chemical engineering, aerospace, atomic energy and other industrial sectors, its application fields are very widely. For example, the expandable graphite can be used as a flame retardant, and is used for fireproof plastic products, fire retardant composite materials and products;

　　The expandable graphite can be used as a multi band stealth smoke agent and shielding materials, it’s widely used in the military field. The flexible graphite products which is made of expanded graphite was known as the "seal of the king." it plays an important role in the field of mechanical seal, fireproof material; the expanded graphite can be used as a sorbent material for recycling of waste and wastewater treatment as the microbial carrier in the field of environmental protection.

　　High purity graphite generally refers to the amount of carbon containing more than 99.99% of graphite in the organizational structure can be divided into three categories: coarse grain structure, fine grain structure and fine grain structure. The base material for integrated circuits is mainly single crystal silicon chip, silicon single crystal growth process is currently mainly used in Czochralski (CZ) method, and other methods of magnetic Czochralski method (MCZ), regional (FZ) method and double crucible pulling method, the total amount of single crystal silicon 80% monocrystalline silicon with the global electronics industry. Czochralski graphite furnace is monocrystalline silicon using consumables, high purity graphite materials into the heating system of monocrystalline silicon furnace. In 2005 China needs to be directly drawn silicon single crystal furnace with graphite about 800 t. [1]

　　Another important use of high purity graphite is processed into various kinds of crucible, used for the production of precious metals, rare metals or high pure metal, non-metallic materials. Graphite electrode is also a kind of high purity graphite, which can be used for the spectral analysis of all elements except for carbon. The impurity content of finished product should be less than 6*10 were prepared by chemical method and standard sample collection for impurity spectrum of pure carbon powder or graphite pure spectrum in spectrum analysis, the two kinds of high purity materials of impurity content requirements are at 6 *10; in some cases, to the carbon content reached 99.9995% the total ash content of less than 5 *10. The molding methods of high purity graphite include three kinds of forming methods, such as extrusion, molding, and static pressing. Table 9 the physical and chemical properties of high purity graphite products made in China

　　In the Medium-grain structure graphite is the particle size in 2 a 0.8 mm of special graphite, with high temperature resistance, oxidation resistance, low content of impurities, single large size, low manufacturing cost advantages. It is used for polycrystalline silicon ingot furnace, various graphite components of crystal thermal field. In the early stage, these parts are made of graphite imported from abroad, and even produced in foreign countries. The price is expensive, a small size single crystal furnace thermal field more than 400 thousand yuan. After several years of development, we designed a special medium breaking system, produce their own special vibration equipment, introduced the high pressure impregnation, tunnel type baking furnace and the internal string type graphite furnace is advanced. Developed a unique production process. My company's crude graphite (all.0 8 mm graphite) gradually reached the requirements of China's crystal silicon production, has been recognized by the majority of customers. At the same time, the product will be pushed to other areas, to the United States, Japan, Europe and other places. Due to the extensive use of domestic crude graphite, coupled with the application of domestic and other static pressure graphite, and now a large single crystal furnace thermal field is only 200 thousand yuan, and still continue to decline

　　In the continuous development of the photovoltaic industry, we are also in the continuous efforts, we will continue to improve the coarse graphite, to improve his performance, increase his size, expanding his capacity of coarse graphite better for crystalline silicon production services, services for the photovoltaic industry.

　　In recent years, with the vacuum heat treatment furnace level improving, the vacuum heat treatment won the favorite of some professional people because it has a series of advantages such as degassing, degreasing, anaerobic and automation and so on , but the vacuum heat treatment furnace has a high standard to electric heating element, the deformation, fracture and volatilization of high temperature electric heating element are the important factors of restricting the development of vacuum furnace. In order to solve this problem, we look to the "black gold" graphite. Graphite has the spotless advantages compared with other metal material ,so the graphite, as the heating element, almost can be used in different types of vacuum heat treatment furnace.

　　The advantages of graphite as the electric heating elements in vacuum furnace:

　　High temperature resistance: the melting point of graphite is 3850±50℃, the boiling point is 4250℃, even it is fired in the ultra high temperature by electric arc, its weight loss is very small, the thermal expansion coefficient is very small, the strength of graphite will enhance with temperature increased, in 2000℃, the graphite strength improve a times.

　　The conductive, thermal conductivity: the conductivity of graphite is 100 times higher than that of general non metallic minerals. Its thermal conductivity is also higher than steel, iron, aluminum and other metal materials. The thermal conductivity decreases with the increase of temperature, even in skyscraping temperature, graphite become an insulator. Graphite can conduct electricity because each carbon atom in graphite will only form 3 covalent bonds with other carbon atoms , each carbon atom still retained 1 free electrons to transfer the charge.

　　The lubrication performance:the lubrication performance of graphite depends on the size of graphite flake, the bigger the scale, the smaller the coefficient of friction, the better the performance of the lubricant.

　　The chemical stability: the graphite has good chemical stability, acid resistance , corrosion resistance and solvent resistance at room temperature.

　　The plasticity: the toughness of graphite is good, it can be rolled into thin sheet.

　　The thermal shock resistance: the graphite can’t be damaged and withstand the severe changes in temperature when we use it at room temperature. the volume of graphite change is not large and has no cracks when the temperature change suddenly.

　　In the vacuum furnace design and processing, we need to consider the resistance of the electric heating element with a smaller change in temperature, the resistivity is stable, so the graphite is used as the preferred material.

　　1).The High Purity Graphite

　　The high purity graphite generally refers to the amount of carbon containing more than 99.99% of graphite and in the organizational structure it can be divided into three categories: coarse grain structure, fine grain structure and ultra-fine grain structure. The basic material of the integrated circuit is mainly silicon single crystal chip, at present silicon single crystal growth process is mainly uses in Czochralski (CZ), Czochralski silicon accounted for about 80% of the total amount of silicon in the global electronics industry, the graphite piece in Czochralski silicon furnace is a consumable,we use the high purity graphite material to process the Czochralski silicon furnace heating system.

　　Another important use of high purity graphite is process various kinds of crucibles which are used for the production of precious metals, rare metals or high pure metal, non-metallic materials. The graphite electrode used in sectral analysis is also a kind of high purity graphite, which can be used for the spectral analysis of all elements except for carbon. The extrusion method is used for the graphite electrode for spectrum analysis ,the impurities of finished product should be not more than 6*10-5 ,in spectrum analysis in preparation of standard sample and catching impurities set required spectral pure carbon powder or spectral pure graphite toner by chemical method. These two kinds of high purity materials of impurity content requirements are in 6*10-5; in some application,it need the carbon content up to 99.9995% and total ash content less than 5 * 10-6. The molding methods of high purity graphite include three kinds of forming methods, such as extrusion, molding, and isostatic pressing.

　　2). The Graphite Material Used in Nuclear Power

　　The graphite is one of the materials used in the construction of nuclear reactors and one of reflective materials,the early reactors are graphite reactor. The graphite as the structural material of nuclear reactor is more strict and expensive in the selection of raw materials, process control, product inspection than the graphite electrode, the grphite used in a nuclear reactor must have the following properties: the little absorption for slow neutron , good high temperature strength, high thermal shock resistance, the good deceleration performance for the fast neutron, stable dimension under irradiation, impurity content rarely. For Boron, Cadmium and other easy absorb elements in the neutron ,we must control the content strictly. The nuclear graphite must have higher bulk density, The bulk density is one of the main indicators of nuclear graphite, The porosity and permeability must be reduced to a certain level. The mechanical strength of graphite is also related to its bulk density. The bulk density of graphite used in the normal graphite reactor is 1.7-1.75g/cm3.

　　3).The Homogeneous Graphite

　　Although the definition of homogeneous graphite need to be defined in the world, the general is measuring the diameter direction and lengthwise direction of some physical properties of the index and calculate the ratio, some with thermal expansion coefficient ratio, the most simple one is expressed as a ratio of the resistivity, the difference to referred to in ~ 1.1 range for isotropic products, more than 1.1 called the anisotropy product. Japan and other industrial technology advanced countries use static pressure molding method of large-scale production of isotropic graphite and the diameter can reach 1.5m, length of 3%, the volume density reached 1.95-2.0g/cm3, the anisotropy ratio reduced to 1.05. In addition to the use of general petroleum coke, the use of modified pitch coke, natural pitch coke, oxidized petroleum coke, calcined petroleum coke, natural graphite, etc., are also used in the manufacture of homogeneous graphite.

　　The graphite heating unit is the electric furnace heating heater parts which are made of the graphite materials.

　　The graphite has excellent electrical conductivity and thermal conductivity. In the special industrial furnace, graphite is used as a heating unit. In the early selection of industrial furnace , the graphite electrode is the heating unit, the high density of high power electrode is used as heating unit later (smelting quartz glass also use graphite electrode as the heating unit). Along with semiconductor industry development, the heating furnace which refine silicon, single crystal germanium, gallium, indium, indium and other materials select high purity ,fine structure graphite and isotropic graphite for heating. Some special industrial furnace and experimental furnace used carbon cloth or graphite cloth as the heating unit.

　　As the graphite heating unit in heating furnace should generate stable thermal field, so the requirements of graphite is uniform texture, stable electrical resistivity. For the graphite heating unit which manufacture single crystal, it require special graphite clean to avoid the effect of impurities for crystal purity and the total ash content should be less than 20 * 10 - 6, and some require up to 5 x 10 - 6.

　　The heating furnace unit has a variety of body shape, cylindrical shape, disc shape ,square canister shape, square disk shape, rectangular plate shape etc..

　　The graphite heating unit often appear deformation phenomenon in the process of using , this is due to the creep caused by graphite. At room temperature, the graphite creep is very small, when the temperature rises to 1700 degrees Celsius or higher, after a few hours, the creep can be observed, the residual strain in the material after the stress is eliminated and resulting in plastic deformation of graphite heating unit. Reflected in the actual use of graphite deformation caused by thermal field is not uniform, the larger the size , the deformation the smaller, the smaller particles graphite is in larger deformation than the bigger particle size graphite.

　　The way to prevent the graphite heating unit deformation : before use it , empty burning the (first ohmic heating) heating unit which is supported by bracket , the air sintering temperature should be greater than the actual use temperature of 100 to 200 DEG C. In order to eliminate the thermal stress cause the graphite heating unit deformation, some manufacturers will use the graphite which the maximum grain size is changed from 0.075mm to 0.5 ~ 1mm to make the graphite heater unit , and it has achieved good results.

　　In July 2012, scientists at the Keel University and the University of Hamburg, Germany, developed the Flying graphite

　　The world's lightest material "flying graphite" (Aero graphite), its density is only 0.2 mg / cubic centimeter, replaced the air gel became the world's lightest material. Looks like a black opaque sponge, made up of 99.99% air.

　　This new material has a stable performance, good electrical conductivity, ductility and very strong. It is composed of a porous carbon annotate in the nanometer and micron scale, which is composed of a mesh structure. Although its quality is very light, but the flexibility is very good, has a strong anti compression capacity and tension load. It can be compressed to 95%, and then restored to the original size. It can absorb almost all the light.

　　Advantage

　　1, stable performance;

　　2, with good electrical conductivity;

　　3, strong extension

　　4, very stable

　　Purpose

　　1. Flying graphite is mounted on the electrode of lithium ion battery, the battery need electrolyte solution becomes less and less, battery quality thus greatly reduced, small cell can be used in electric car or bike.

　　2 can make the composite material with electrical conductivity, so as to avoid electrostatic interference.

　　3 can also be applied to the electronic equipment used in the aerospace and satellite fields, because these devices must be able to withstand a large number of vibration.

　　4 is expected to be used in water purification, as an adsorbent for the adsorption of pollutants in water, because it can oxidize or decompose and remove pollutants in water.

　　5 can be used in the constant temperature box or ventilation equipment to purify the environment air.

　　Beijing Great Wall Co., ltd is a leading company of graphite product. We always offer the best quality and the competitive price for our customer. We are looking forward to your enquiry and cooperation in the future.