To explain the basics of tungsten metal

Family in the non-ferrous metals, tungsten maintain the "high-temperature Champion" long centuries. The world's first discovery of tungsten, the Swedish chemist Club Le. He first used in 1781 tungstate acid decomposition obtained tungsten element. Then, and after a period of painstaking research, only in 1848 the system out of pure tungsten. Pure tungsten silver-white, very beautiful, the proportion 19.1t/m3. Superior performance of tungsten is chemically stable, even in heated situations, nor and hydrochloric acid, sulfuric acid works, even in aqua regia will not be dissolved. Tungsten temperature, known as the hardest natural metal melting, melting point up to 3410 ℃; hardness of tungsten metal in the top, only heated to a high temperature in order to pressure processing. Uses unique tungsten has many unique uses, such as high hardness, tungsten carbide inserts, tungsten steel can be manufactured. Tungsten steel tools, high strength than ordinary steel tools several times or even several times; tungsten steel barrel, barrel, firing in a row, even when the barrel is too hot projectile friction, can still maintain good flexibility and mechanical strength. In the metal cutting machine tools, turning tools made of tungsten steel, temperature up to 1000 ℃ still hard as before. A solution of 3% to 15% of tungsten, tungsten-chromium-cobalt alloy plating or welding the parts of the surface of ordinary steel, it is equivalent to the parts wear hard "armor", both temperature compressive strength, but also resistance to corrosion, reduces wear life can be extended several times. Because of the superior properties of tungsten steel and broad purpose, the world's annual production of tungsten, 90% are used to produce tungsten steel. Tungsten plasticity. A 1 kg weight of tungsten rod, you can pull grow about 400 km, diameter of only 1% mm filaments. Such filaments at 3000 ℃ high temperature environment, still has a certain intensity, and high light, long life, is to create a variety of light bulb filament of good material. Incandescent, tungsten, and even the world's most innovative lamps, are manufactured with tungsten. The United States has used a new type of solid fuel, the rocket gas temperature exceeds 3000 ℃. In this case, the hardest melting tungsten nozzle too overwhelming. Scientists through research, manufacturing a new type of tungsten alloy - "self-cooling permeability porous tungsten alloy of silver." When the rocket flying high in the air, this new alloy with high temperature and pressure nozzle, spray continuously sparkling flames. The nozzle surface infiltration of silver at a high temperature first evaporated while absorbing the heat of evaporation. Thus, to achieve automatic cooling purposes and to prevent excessive temperature rise, the badly baked nozzle 3000 ℃ high temperature, is still able to maintain the original character.

Introduction and use of tungsten

Tungsten wire  (English TungstenAlloys; abbreviated W-Alloys) (a) Product description: Tungsten gold is rare in the world a colored minerals, annual output is very low, very versatile ingredient of material is mainly used for casting. Tungsten ore from a white sand, ore line especially tiny, after mining, milling, water re-election, refining and other multi-channel technology, get up 95_ above grade tungsten ore, and then through the high-temperature furnace to produce refined shape the finished product is tungsten. Melting point of tungsten: 3500 ℃. Tungsten present mainly in China and Russia, China is now the world's largest exporter of tungsten. Typically the purity tungsten should at 99.95_ or more, and must be issued by authority of the examination and analysis test reports, for example: non-ferrous metals and electronic materials analysis and testing center analysis test report. (Two) Usage: 1, processing car knife blade, tungsten lighting equipment and a variety of thermal conductivity with 2 advanced automobile crankshafts, cylinder ingredients, heat-resistant steel casting various ingredients 3, widely used in firearms, artillery, rockets, satellites, aircraft and ship

Molybdenum widely

Molybdenum crucible is an essential trace element the human body, animals and plants. The silvery white metal, hard and tough. Various human tissues are molybdenum, adult body total 9mg, liver and kidney of the highest concentrations. Molybdenum is mainly used for the steel industry, most of which is used directly after briquetting industrial molybdenum steel or cast iron, a small part before melting into molybdenum used in steelmaking. Stainless steel, molybdenum is added, to improve the corrosion resistance of steel. Adding molybdenum in cast iron, iron can improve the strength and wear resistance. Pure molybdenum wire for high temperature furnace and wire cutting EDM there; molybdenum sheet used to manufacture radio equipment and X-ray equipment; molybdenum high temperature ablation, mainly for artillery bore, rocket nozzle, tungsten light bulbs manufactured stent . Plus molybdenum alloy steel can improve the elastic limit, corrosion resistance and to maintain permanent magnetism, molybdenum is required for plant growth and development in the seven kinds of micro-nutrients in one, without it, the plants can not survive. Animals and fish, and plants that also need to molybdenum. In other areas of molybdenum alloys and chemical fields of application are also expanding. Mo in thin-film solar and other coating industry, as the membrane surface of the substrate different have been widely used. Molybdenum matrix by adding other elements consisting of non-ferrous alloys. Major alloying elements are titanium, zirconium, hafnium, tungsten, and rare earth elements. Titanium, zirconium, hafnium, molybdenum alloy element not only from solid solution strengthening effect, maintaining low alloy ductility, but also form a stable carbide dispersed phase, increase the tensile strength and the recrystallization temperature. Molybdenum alloy has good heat conductivity, and low coefficient of expansion. Molybdenum alloy is the main way to strengthen the solid solution strengthening, precipitation strengthening and work hardening. Molybdenum in the twenty-first century is widely used in manufacturing weapons and equipment, modern high-precision and advanced equipment, the material requirements are higher, such as molybdenum and tungsten, chromium, vanadium alloys for the manufacture of ships, rockets, satellites alloy member and components.

Molybdenum products are effective enhancer

molybdenum plating products are very effective enhancer, can improve the creep strength of the steel to be used at about 600 ℃ degree, molybdenum products for low carbon microalloyed HSLA steels played an important role, adding 0.1% to 0.3% Molybdenum can be refined acicular ferrite grain structure, increased molybdenum content to increase stainless steel pitting corrosion resistance and crack, and may enhance other alloying elements obtained from the precipitation hardening effect. Molybdenum is a special steel alloy elements, Mo not only into its many excellent properties in the steel, but also be easily added to the molten metal, molybdenum is used for carburizing of steel products, the core portion can be improved carbon parts The hardenability, while increasing the toughness of carbon parts, molybdenum products for large cross-section of parts, such as gears, etc., are particularly effective, molybdenum products during carburizing molybdenum is not oxidized, as an effective hardening agent, molybdenum products not cause surface cracks and peeling. Molybdenum is to prevent pitting corrosion and crevice corrosion in the most efficient and lowest cost of alloying elements molybdenum steel is to improve resistance to stress corrosion cracking one of the most effective methods, molybdenum is one of the earliest applications in tool steel and high-speed Steel is used as a substitute for tungsten, molybdenum, stainless steel was severely corroded, in extremely harsh operating environments scrubber power plants, pulp and paper and chemical processing equipment requires the use of very high molybdenum content of the alloy .

Pyrolytic carbon molybdenum alloy for injection molding properties and microstructure of two people reading

Prepared by powder injection molding Mo-Ti-Zr alloys, studies on thermal decomposition of carbon-molybdenum alloys and organizational impact. The results show that the carbon content is low, the alloy density is increased, and the carbon to form the dispersed second phase particles, such alloys have been strengthened; the carbon content is high, it is easy to add the elements molybdenum plating substrate and brittle second phase formed by the reaction particles, these second-phase particles in the fracture under tensile stress, coupled with the injection of the sample itself, there are more holes, cracks easily become a source of the alloy decrease in performance. Pyrolytic carbon can effectively prevent impuritiesowever, molybdenum has a low temperature brittleness, low strength, ductility and poor is insufficient, molybdenum alloy deep processing more difficult, its application is more restricted. Over the years, the production of Molybdenum Molybdenum primary products. Therefore, the development with better performance, higher value-added molybdenum alloys, molybdenum industry for the development of our country has an important significance.
Sun Jun engineering research group from the actual needs, dating back to the difficulty of material preparation techniques, revealing the rare earth oxide doped Molybdenum tube alloy grains and intragranular and grain boundary

while the tensile ductility doubled

In the National Natural Science Foundation and other projects funded by the [1] Materials, Xi'an Jiaotong University, State Key Laboratory Sun Jun Task Force successfully developed nano-structured dispersion strengthened molybdenum alloys. The material has a rare earth oxide nano-particles and ultrafine-grained microstructure reinforced structure, while the tensile ductility doubled.
China's molybdenum reserves, production and consumption volume ranking first in the world. Molybdenum is widely used in stainless steel and other materials for the production of steel, molybdenum alloys also because of their excellent thermal conductivity with a high temperature and other characteristics, in the aerospace, machinery, metallurgy and other fields has broad application prospects.
However, molybdenum has a low temperature brittleness, low strength, ductility and poor is insufficient, molybdenum alloy deep processing more difficult, its application is more restricted. Over the years, the production of Molybdenum Molybdenum primary products. Therefore, the development with better performance, higher value-added Molybdenum tube alloys, molybdenum industry for the development of our country has an important significance.
Sun Jun engineering research group from the actual needs, dating back to the difficulty of material preparation techniques, revealing the rare earth oxide doped molybdenum alloy grains and intragranular and grain boundary characteristics and particle size effect toughening mechanism, a robust of quantitative analytical model and proposed toughening of nano-doped new ideas.
On this basis, the researchers developed a molecular liquid doped rare earth oxides prepared by mixing nano-molybdenum alloy containing key technologies to solve the rare earth oxide nano-and non-reunion of the molybdenum grains and grain boundaries uniformly dispersed and nano ultrafine grain structure constraints such as high temperature stability of development of the sector three key issues. They prepared molybdenum alloy strength and extension, than has been reported toughness international class companies best level similar materials, while significantly lower plastic brittle transition temperature, high alloy recrystallization temperature and high temperature tensile strength and ductility significantly.
It is reported that the relevant technologies have to achieve industrial-scale applications, the project also received the 2012 Ministry of Education, Technological Invention Award.
Edit this paragraph

the rolling temperature can be reduced to 700 ~ 900 ℃;

Cast for crushing coarse grain, improve ingot processing performance, can also be used to produce tubes, rods and profiles. In order to fully cast grain crushing, extrusion ratio should not be less than 4, the extrusion temperature is usually between 1100 ~ 1315 ℃. If it is directly obtained by extrusion products and intermediate products shall adopt greater extrusion ratio and higher extrusion temperature. To extend the die life and the dimensions and surface quality assurance products should be used or a zirconia refractory aluminum oxide coating die, extrusion glass lubricant lubrication.
Forging
Including swaging and general forging. Mainly for the production of swaged over 2.5 mm diameter rods and pull the wire drawing of the blank material, the use of the blank 10 to 30 mm square sintered article. Pure molybdenum swaged forging temperature often open about 1400 ℃, pass deformation is generally 10 to 20%, also up 30%. As the diameter decreases, the temperature gradually decreased forging 3 mm diameter can be reduced to about 800 ℃. For ordinary forging, the forging press forging is more desirable than. General availability of large forging billet and large forgings. Pure molybdenum open forging temperature of about 1400 ℃, while the extruded billet billet open open forging temperature can be lower. Free forging pay attention to safety, to prevent the workpiece or fragments flying out.
Rolling
For sheet, strip, foil and bar production. Rolling smelting - extruding the billet to provide the initial rolling temperature is generally between 1200 ~ 1250 ℃; powder blank provided the initial rolling temperature is generally at about 1400 ℃. To reduce the non-uniform deformation, the roughing pass deformation should be 20 to 40%, and the total rolling time after heating deformation of about 75%. When the amount exceeds 85% of total deformation (thickness of about 6 mm), the rolling temperature can be reduced to 700 ~ 900 ℃; thickness of 1 to 2 mm, the rolling temperature can be reduced to 200 ~ 400 ℃. The plastic based material - brittle transition temperature type, the transition to the cold rolling sheet thickness of 0.5 to 1 mm. Cross-rolled products can be used to improve the anisotropy. Hardening to obtain sufficient plasticity and improve the low temperature, the appropriate amount of cold working the end product should be 70% or so.
Mainly in the processing of molybdenum tubing pipe sintered ingots as extrusion ingots or billets, using temperature processing technology, by rolling, drawing or spinning into various pipe. China used to produce small diameter warm rolling molybdenum tube. Blooming temperature is generally about 650 ℃, the final rolling temperature is about 350 ℃. Warm rolling pass processing rate is generally 20 to 35%, up to 40%. For a diameter of 8 mm, wall thickness of 0.5 mm molybdenum plating tube, the tube can be rolled up to 6500 mm. Have a good warm-rolled molybdenum tube inner and outer surfaces, good room temperature ductility and further pulled into the capillary. Large diameter thin-walled tube for general use extruded or sintered tube and then by spinning processing.