Pyrolytic graphite is a new type of carbon material, it is the high crystallinity pyrolytic carbon under the high pure hydrocarbon gas in the furnace pressure and one the graphite matrix which is in 1800 DEG C to 2000 C through the chemical vapor deposited, it has a high density (2.20g/cm), high purity (impurity content is 0.0002%) and the heat, electricity ,magnetism and mechanical properties anisotropy . The vacuum degree of 10mmHg can still be maintained at about 1800 DEG C.

　　Pyrolysis is the process of decomposition of a substance by heat. The decomposition reactions will occur when many inorganic substances and organic matter are heated to a certain degree .The pyrolysis process does not involve the reaction of the catalyst and other energy, such as UV radiation. Pyrolytic graphite is obtained through this process.

　　The main characteristics of pyrolysis graphite:

　　The surface of pyrolytic graphite is dense and without the pore , so it is easy to machine.

　　Pyrolytic graphite has high purity, total impurity content is less than 20ppm, it’s in good air tightness.

　　High temperature resistance, the strength of the pyrolytic graphit increased with the temperature increasing, the strength reached the highest value at 2750℃and it will sublimate in 3600℃.

　　The pyrolytic graphite products have the low elastic modulus, high thermal conductivity, low thermal expansion coefficient and the good thermal shock resistance.

　　Pyrolytic graphite has good chemical stability, it can bear the acid, alkali, salt and organic reagent and has no effect with molten metal, slag and other corrosive media , its oxidation is not obvious in the atmosphere and the temperature below 400℃, the oxidation rate increased significantly at 800℃.

　　The pyrolytic graphite does not release any gas under high temperature and can maintain the vacuum of 10-7mmhg at about 1800℃.

　　Pyrolytic graphite is mainly used in graphite heater, diversion barrel, PBN/PG composite heater and atomic absorption tube.

　　Polyacrylonitrile (PAN) based graphite felt , made of PAN precursor in an inert gas in high temperature and antipyretic have a variety of forms, such as continuous products, carbon fiber, short carbon fiber and short carbon fiber. It has many applications in engineering because of its excellent physical and chemical properties and electrical conductivity. Continuous carbon fibers are often used in resin matrix composites as reinforcements.

　　The most widely used short cut carbon fiber is a small amount of chopped carbon fiber mixed with concrete, forming carbon fiber concrete, which has a variety of functional characteristics such as pressure sensitivity, temperature sensitivity, thermoelectric and electrothermal effects. Based on the above features, carbon fiber reinforced concrete materials can be used in the temperature and deformation self diagnosis and adaptive aspects of concrete structures, such as intelligent deicing and snow melting system of concrete pavement [5]. But the production process of continuous carbon fiber is relatively complex, the price is higher; and the short cut carbon fiber mixed with concrete, need the chopped carbon fiber completely uniformly dispersed in the concrete, it is a big problem in materials, the functional properties of carbon fiber reinforced concrete material is affected, especially the heating effects the size based conductive network formation in carbon fiber, namely by carbon fiber components reduce the concrete resistance and Joule heat.

　　Graphite felt is a soft cloth formed by the bonding of chopped carbon fibers, and each fiber forms a conductive network with each other. In the concrete smart materials, because the carbon fiber felt easily cut into the desired shape size, sample only need to be paved in concrete.

　　PAN based graphite felt with electrothermal effect good and stable; the thermal efficiency of carbon fiber of different types are different, therefore, can choose the optimal thickness, to achieve efficient and economic purposes; in a certain temperature range, the temperature stability of PAN based graphite felt the rise and the input power is proportional to the input power can be selected according to the need the temperature rise; graphite felt with a temperature sensitive effect, linear resistivity increased with the temperature of graphite felt decreases, this effect can be used for temperature detection structure; combined with temperature sensitive effect and heating effect, is expected to realize the adaptive temperature regulating structure.

　　Ammonia decomposition produced by urea nitrogen doping on graphite felt, preparation of nitrogen doped graphite felt, compared with nitrogen doped graphite felt and graphite felt has more excellent electrochemical performance, and doping temperature and doping time have influence on the electrochemical activity of graphite felt.

　　Proton exchange membrane fuel cell (PEMFC) has many advantages, such as high power density, low working temperature, fast start and long service life, but hydrogen storage is used as fuel.

　　Graphite felt is the main cathode material of direct flow methanol fuel cell, and its performance is very important for direct flow methanol fuel cell. Graphite felt has the advantages of good stability, large surface area under unit cost, good fluid permeability, etc. but its application is limited because of its poor hydrophilicity and low electrochemical activity.

　　Commonly used acid treatment, heat treatment, electrochemical oxidation, nitrogen doping and other methods. Due to nitrogen doping not only improves the surface chemical activity of graphite felt, but also on the electronic structure of regulation, so in recent years, nitrogen doped graphite felt in many electrochemical devices exhibited electrocatalytic properties better than graphite felt no nitrogen doping of this study is based on previous achievements.

　　The ammonia produced by hydrolysis of urea by nitrogen doping treatment on graphite felt, has an important influence on the electrochemical activity of the cathode temperature,nitrogen doping does not change the crystal structure of graphite felt, but will affect the crystallite parameter.

　　there will not be much affected the overall morphology of nitrogen doped under certain conditions on the graphite felt mat, the nitrogen content of graphite are improved in nitrogen doped after nitrogen increased mainly pyrrolic nitrogen and pyridine type nitrogen, indicating the increase of no contribution even inhibit the electrochemical activity of graphite nitrogen on graphite felt, pyrrolic nitrogen and pyridine type nitrogen is the main reason to enhance the electrochemical activity of graphite felt the.

　　Graphite has high temperature strength, low thermal expansion coefficient, good mach inability and good heat and conductivity, so graphite electrode is widely used in metallurgy, electric furnace, EDM and other fields. In the field of EDM, the development of new graphite electrode material and its processing technology expands the application range of EDM and improves its performance. Compared with the graphite electrode and the copper electrode has the advantages of electrode consumption, fast processing speed, good machining performance, high processing precision, small thermal deformation, light weight, high temperature resistance, easy processing, surface processing of high temperature, electrode bonding etc.. Although graphite is a very easy cutting material, but because the graphite materials used for EDM electrode must have sufficient strength to avoid damage during operation and EDM process, at the same time, electrode shape (thin, rounded, sharp change) and also put forward higher requirements on the graphite electrode and the grain size and strength, which leads to in the process of graphite work piece easily broken, the tool is easy to wear. So how to prevent the work piece from crushing, improve the surface processing quality and reduce the cost of processing tools become an important problem of graphite electrode processing. Conventional turning, milling and grinding methods can meet the demand of machining simple shape electrodes, but the requirement of electrode geometry complexity has been increasing in recent years. High speed machining high surface quality and high processing precision make graphite electrode high speed machining has become a hot spot in mold EDM processing,

　　Finishing should make the processing stable, have smaller shape error and good surface quality, at the same time the tool wear is small. Tool wear and machining costs are major considerations. In finishing machining, the influence of milling direction on machining precision and surface quality should be taken into account. In the feed milling along the surface will appear pull milling (upward knife) or drilling and milling (down knife) phenomenon, tool deformation will lead to work piece contour deviation. The contour deviation of drilling and milling is less than that of drawing and milling, and the contour deviation of reverse milling is better than that of forward milling. Therefore, considering the critical condition of tool quality and the stability and reliability of machining process, the best method of milling along the contour should be the combination of reverse milling and plane contour milling. In addition, when the milling, the envelope contour milling tool life is greater than drilling milling, reverse milling when the two almost.

　　Graphite is an important strategic resource，and China’s graphite resource reserves and production rank the first in the world. High purity graphite has excellent performance and graphite products are widely used. Purification of graphite is the premise and basis of graphite products application，therefore the performance and application of graphite products are directly affected by the purity of graphite. Graphite resource and production and consumption in China and the rest of the world are presented. The main methods for purification of graphite are discussed，and the research progress of graphite purification are reviewed from several aspects，including flotation method， alkali-acid processing method，hydrofluoric acid washing，chloridizing roasting and high temperature purification. After comparing the advantages and disadvantages of each method，the development direction and prospect of graphite purification is put forward. Grinding and flotation technology for protection of larger graphite flake，less fluoride or fluoride-free graphite purification and cost-effective high temperature graphite purification will be the new technologies in the future.

　　As the purification of graphite is the prerequisite and basis for the development and application of graphite materials, the demand for high purity graphite will be increased with the improvement of the application level of graphite. The purification of graphite should be adapted to local conditions, and the development of resource saving and environment friendly.

　　Graphite as a kind of important strategic resource and our country's advantage resources, need to develop the deep processing and application of graphite industry. Graphite purification technology to floatation purification technology as the foundation, according to the graphite product application field and application way requirements, in order to deepen the alkali acid, hydrofluoric acid, high temperature method and purification technology. The development trend of the purification technology will be the development of high temperature purification technology with the protection of large scale integrated grinding flotation technology, the low fluorine and fluorine free purification of acid and alkali substitution technology and the realization of superior cost-effective.

　　The carbon fiber-reinforced polymer material are made of high strength carbon fiber and vinyl resin by pultrusion process and winding twining and coating technology.

　　The product features of the CFRP material:

　　light quality and high strength . The most outstanding advantage of CFRP material is that it has high specific strength (ultimate strength / relative bulk density), which is usually called light quality and high strength..

　　The good corrosion resistance. CFRP can resist chemical corrosion in acid, alkali, chloride and humid environment, which is difficult to reach by traditional structural materials.

　　The elastic properties of CFRP material are good, the stress-strain curve is close to linear, and it can restore the original state after the larger deformation, and the plastic deformation is very small, which is more favorable for the structure with large dynamic load.

　　The application of the carbon fiber-reinforced polymer material:

　　On the concrete bridge structure: every winter we will spread a large number of salt in the bridge, on the road to prevent freezing. But the corrosion of brine to traditional reinforced concrete bridge is very serious. The use of carbon fiber-reinforced polymer material can greatly reduce the bridge corrosion problem, reduce maintenance costs and increase bridge service life.

　　In the road construction: in road construction, the concrete pavement and prestressed concrete road need to improve durability. It will exacerbate corrosion of rebar because of the use of antifreeze Salt Road,the CFRP material show great advantage in solving the problem of corrosion prevention, .

　　In the harbor, wharf and other fields of concrete structure: all of the high ground parking lot, parking lot and underground parking lot have the winter antifreeze problems, many of the rebars of the buildings in coastal areas bear the corrosion of sea salt in the sea breeze and are obvious deterioration. Therefore, all kinds of situations need to use carbon fiber-reinforced polymer material.

　　In the anti-corrosion construction: domestic wastewater and industrial waste water is a major corrosion roots of rebars and other gaseous, solid and liquid chemicals can also cause corrosion of rebars. While the corrosion resistance of the carbon fiber-reinforced polymer material is better than rebars,so it can be used widely in the sewage treatment plant, wastewater treatment equipment, petroleum chemical equipment.

　　The correct or incorrect operating method of graphite crucible will impact its service life directly , it need the coordination with crucible furnace when we use the graphite crucible, now ,we introduce the relationship between the graphite crucible and crucible furnace.

　　The graphite crucible and the crucible furnace can not be separated. the application environment of graphite crucible become more and more brutal when we improve the working efficiency of the crucible furnace. On the contrary, the performance and the shape of the crucible furnace have been changed because of the quality improvement of the graphite crucible and the beginning of the large-scale crucible.

　　In recent years, with the continuous improvement of environmental equipment of foundry machinery, the continuous improving degree of the mechanization ,the hydraulic tilting crucible furnace has gradually been adopted. Especially in the high temperature melting and the large copper alloy casting factory , the popularity rate of tilting crucible furnace is very high. So we should have a correct operation method when we use it , it has its life.

　　The materials should be arranged in a graphite crucible vertically . The aluminum Ingot contacts with the crucible side wall askew due to the thermal expansion of graphite crucible, there is a possibility to squeeze rupture to graphite crucible. please note that the remaining soup shouldn’t be left when we bail the melt out. The remnants solidification melting will expand rapidly and cause the fracture of the crucible in the next time melting. For the combustion in the graphite crucible,the attention must be paid to the furnace design and adjustment of the burner for complete combustion in the lower crucible and under the crucible.

　　We believe that through the above introduction, we will have a greater understanding of the relationship between the graphite crucible and crucible furnace, in the future application process, the more understanding of these knowledge is very useful for us .

　　We annual output of 5000 tons of carbon fiber precursor project was completed and put into production in September 5, 2011,and self-developed the wet two-step spinning process has gotten national invention patent.Through continual innovation and development, by end of July 2017, the output of the carbon fiber precursor wasexpanded to 20000 tons; the quality has reached the level of T700; Sales increased exponentially year by year,, the domestic market share of more than 50%, and successfully enter the international market, and become toChina's largest carbon fiber precursor production base。The company has built an annual output of 200 tons carbonization experiment line and complete carbon fiber and precursor inspection instruments and equipment.

　　We has developed into the carbon fiber manufacturer of carbon fiber precursor, carbon fiber, preoxidized fiber, high-strength industrial fiber as a whole,with obvious advantages of industrialization due to thelarge tow low cost. Products are 1K, 3K, 6K, 12K, 24K, 48K, carbon fiber precursor, carbon fiber and related products,and has been widely used in sports, industry, construction, automobile, military, aviation, aerospace and other fields.

Product Details

　　We annual output of 5000 tons of carbon fiber precursor project was completed and put into production in September 5, 2011,and self-developed the wet two-step spinning process has gotten national invention patent.Through continual innovation and development, by end of July 2017, the output of the carbon fiber precursor wasexpanded to 20000 tons; the quality has reached the level of T700; Sales increased exponentially year by year,, the domestic market share of more than 50%, and successfully enter the international market, and become toChina's largest carbon fiber precursor production base。The company has built an annual output of 200 tons carbonization experiment line and complete carbon fiber and precursor inspection instruments and equipment.

　　We has developed into the carbon fiber manufacturer of carbon fiber precursor, carbon fiber, preoxidized fiber, high-strength industrial fiber as a whole,with obvious advantages of industrialization due to thelarge tow low cost. Products are 1K, 3K, 6K, 12K, 24K, 48K, carbon fiber precursor, carbon fiber and related products,and has been widely used in sports, industry, construction, automobile, military, aviation, aerospace and other fields.

Product Details

　　We annual output of 5000 tons of carbon fiber precursor project was completed and put into production in September 5, 2011,and self-developed the wet two-step spinning process has gotten national invention patent.Through continual innovation and development, by end of July 2017, the output of the carbon fiber precursor wasexpanded to 20000 tons; the quality has reached the level of T700; Sales increased exponentially year by year,, the domestic market share of more than 50%, and successfully enter the international market, and become toChina's largest carbon fiber precursor production base。The company has built an annual output of 200 tons carbonization experiment line and complete carbon fiber and precursor inspection instruments and equipment.

　　We has developed into the carbon fiber manufacturer of carbon fiber precursor, carbon fiber, preoxidized fiber, high-strength industrial fiber as a whole,with obvious advantages of industrialization due to thelarge tow low cost. Products are 1K, 3K, 6K, 12K, 24K, 48K, carbon fiber precursor, carbon fiber and related products,and has been widely used in sports, industry, construction, automobile, military, aviation, aerospace and other fields.

Products Details