分类： PHP
2014-05-01 15:23:13
Classification by metal, mainly heavy metals copper, lead, zinc, tin, antimony, nickel, cobalt, chromium, manganese; light metals like aluminum, magnesium; refractory metals like tungsten, molybdenum, tantalum, niobium, vanadium, titanium, zirconium; noble metals gold, silver, platinum, palladium; semi-metal silicon, boron.
Copper powder is one of the important raw materials of metallurgy industry, its consumption is in second place after the iron powder. Except used as raw materials for the powder metallurgy materials, the directly application of copper powder is very extensive, its consumption is only second to aluminum powder. Industry produce copper powder methods are mainly have three kinds: (1) electrolytic method, the powder with high purity, large range of applications, is the main production method that most countries still used today, but there is large power consumption, environmental pollution and other shortcomings; (2) oxide reduction method, the United States atomization granulation?oxidized?reduction process as representation, the powder properties, varieties can be replaced by copper powder, meet the application requirements, and overcomes the disadvantages of electrolysis; (3) Water metallurgy method, have leaching-high pressure hydrogen reduction, leaching-replacement or electrolysis process. Often used for low-grade copper material utilization. The consumption of copper powder accounts for most in industrial applications, because most powder metallurgy copper parts are still suitable for used cold process-sintering pre-mixed powder (copper powder adding elements powder such as tin, lead, zinc powder and mechanical mixing), or part of the pre-alloyed powder (the mixed powder through heat-treated to make diffusion alloying) to produce, such as used for oil-bearing tin bronze powder.
Tin powder, lead powder and zinc powder is mainly used atomization method to produce. Tin, lead, zinc and copper-based alloys is the main alloying elements, so that in the extensive use of copper powder to produce copper-based powder metallurgy materials and products should also add tin powder, lead powder and zinc powder as a raw material component. In addition, it also directly applied in preparing solder flux, rubber and plastic additives, fireworks, metallic pigments and so on.
Tungsten, molybdenum rods, plates, wire is used tungsten, molybdenum powder as raw material to further purify, process to form, also can be through tungsten, molybdenum powder metallurgy process directly produce tungsten and molybdenum shaped products. Tungsten powder also the important raw materials of cemented carbide industry prepare tungsten carbide powder. Tantalum powder is mainly used in manufacturing capacitor, is prepared by potassium tantalum fluoride by thermal reduction of sodium metal. After tantalum powder made of bars though electron beam melting purified and then by hydrogenation, crushing, dehydrogenation process can be prepared high purity tantalum powder and tantalum alloy powder. Niobium powder is made from aluminum thermal reduce niobium oxide and then hydride, crushing, dehydrogenation process the resulting niobium metal. Titanium powder is generally produced by sodium or magnesium thermal reduction method, obtained spongy titanium (titanium sponge) can be further purified, processing titanium and titanium alloy materials, can also be hydrogenated, crushing, dehydrogenation to make of titanium powder. Manganese powder generally produced by mechanical crushing method and used materials are electrolytic manganese metal, industrial application methods include milling method, ultrafine grinding method, vertical mill grinding method and so on.
Noble metal powders are mainly the silver powder applications. Silver powder used for manufacturing battery electrodes and silver-based electrical contact materials, used for the electronics industry conductive inks, ointments and adhesives, etc., also used in dental amalgams, water purification and catalyst. The electricity, electronics industrial silver powder is produced by chemical precipitation method, with high purity, fine grain size and other characteristics, a small amount is also produced by atomization. The production method of gold, platinum and palladium powder are similar to silver powder, mainly used as conductive material in the electronics industry.
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