Dressing Grinding Wheel Specially used for the shaping and sharpening the Diamond/CBN Grinding Plate
Feature:
1. Reasonable ratio of ID & OD, make the dressing more efficient.
2. Specified dressing Grinding Wheel for specified Diamond/CBN grit size and precision.
3. Combine the sharpening and shaping, not only ensure the grinding plate flatness but also sharpen the Diamond/CBN grinding plate.
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Keywords: silver application status quo
Silver is a relatively inexpensive metal in precious metals. It has a very wide range of uses in industry and people's daily lives. It has a great correlation with the industry. It is not only a high-tech metal, but also a military and civilian metal. This article focuses on the ten main areas of silver.
　　 Photosensitive material
The silver halide photosensitive material comprising a silver halide is silver chloride, silver bromide, a photosensitive material, the crystallites are dispersed in the gelatin medium to form an emulsion, and coated on a support and which (film or paper-yl) to make. The size of the silver halide grains required for different photosensitive materials is different, and the commonly used silver halide crystallite size is 0.2 to 2 μm; the silver halide grains used for special purpose films are ultrafine crystals with a size of 0.1 μm ; silver halide hologram The size of the silver halide crystallite used in the photosensitive material is 0.03 to 0.08 μm . To improve the resolution, diffraction efficiency and sensitivity to the laser of the emulsion, a T -grain emulsion has been developed , which is a flat sheet of silver halide grains, T -granules. The thickness is below 0.3 μm , the morphology ratio (ratio of particle diameter to thickness) is >8, and the typical T -particle morphology ratio is >20 . It is difficult to achieve excellent dispersion of silver in T -particle preparation. The advantage of the T -particles is that the surface area is large, the photosensitive layer can be made thinner, and the amount of silver used is reduced. In order to meet different needs, a variety of silver halide crystallites of various shapes and internal structures have been developed.
Silver halide photographic materials are one of the areas with the largest amount of silver. The most photographic materials currently produced and sold are photographic film, photographic paper, medical X -ray film, industrial X -ray film, microfilm, fluorescent information recording film, electron microscope photographic film and printed tip film. In the 1990s , the amount of silver used in the world's photographic industry was about 6,000 to 6,500 tons , and the output of medical X -ray film (including CT ) was 10 times larger than that of industrial X -ray film , and the amount of microfilm was also greatly increased.
Due to the development of technologies such as electronic imaging, digital imaging, and countless touch printing, traditional silver halide imaging technology has been challenged by shocks such as television impacting movies. At the same time, the emergence of high-tech non-silver photographic materials in the printing industry, document reproduction, audio-visual industry, etc., also reduced the amount of silver halide photographic materials, but the application of silver halide photographic materials is still irreplaceable in some respects, still very large Market space.
The large number of applications of silver halide photographic materials make it a source of secondary resources for silver. For example, medical X -ray film needs to be archived. In some countries, children's X -ray film is kept in adulthood. These films use a lot of silver. X -ray film saved by major hospitals in the United States is estimated to occupy 3,000 to 4,000 tons of silver . The use of microfilm technology can save silver.
　　 Decorative material
Silver has an attractive white luster and a reflectivity of 91 % for visible light. It is favored by people (especially women) and therefore has the reputation of " woman's metal " . Silver is widely used as jewelry, decorations, silverware, tableware, congratulatory gifts, medals and commemorative coins due to its beautiful color, high chemical stability and collectible ornamental value.
The most commonly used silver-based decorative alloys are Ag-Cu alloys, Ag-Pd alloys, and hardened silver alloys by adding small amounts of other metal elements. The Cu content in the Ag-Cu alloy ranges from ( wt% ) 7.5 to 2.0 . In the UK, 925 alloy known as Sterling Silver (Sterling Silver), containing Cu 7.5%, was the only currency of alloy, alloy ornaments also. Ag-Cu10% co Gold (900 alloy) called silver currency, jewelry in general more than 800 or 800 alloy. Alloys of Ag-7.5 to 20% Cu can also be used as tableware. Jewelry uses a low palladium content silver alloy to increase corrosion resistance by adding a small amount of Au or Pt . The addition of Cu , Zn , and Sn improves the castability. Pure Ag can be hardened by adding Mg , Ni, etc., followed by internal oxidation, and the silver purity is maintained at 99 % or more. Ag and Au added Pd alloy formed silver alloy. Based on Ag , add 10 to 20 % of Ni or Zn, and 12% of Pd can also produce " Platinum ".
alloy.
The color of a metal or alloy depends on the relationship between its reflectivity and the frequency (energy) of the incident light. Ag and Au have similar electronic structure, it may be desirable throughout the Au-Ag bonding The energy band structure in the gold system is unchanged, but the energy gap between the d energy band and the Fermi level increases continuously as the Ag content increases, and this energy gap width is just the decision to control the color band transition. factor . The electronic structures of Cu and Au are also similar, so Ag is an important constituent element in Au-Ag , Au-Ag-Cu, and Au-Ag-Cu-Zn and K alloys. In the Au-Ag alloy, with different Ag content A series of colors can be obtained, and when the amount of Ag reaches 70 at% (56 wt%) , the alloy becomes white. [next]
Silver jewelry still has a broad market in developing countries, and silver meals are popular with families.
Since the withdrawal of gold and silver from the monetary status, the statutory coin has also withdrawn from the historical stage, but it is still very popular as a commemorative coin. The commemorative coin is the issuing country to commemorate major events in the country and the world. A legal coin issued by historical figures, historical sites, rare animals, plants, etc. The commemorative coins are beautifully designed, with a small circulation, and have the function of maintaining and increasing value. They are well received by coin collectors and coin investors. In the 1990s , the coinage silver remained at around 1000 to 1500 tons , accounting for about 5 % of silver consumption .
　　 Contact material
One of the largest quantities of silver used in the electrical industry is the electrical contact material.
At present, the annual output of silver and silver-based electrical contact materials in the world is about 2,900 to 3,000 tons . There are hundreds of different brands of contact materials in the world, and everything is available. On the one hand, it is due to the increasing demands of modern industry for contact materials, and on the other hand, it is related to the different resources of countries. Some grades have been improved to add some new elements and actually become an alloy of another grade.
In silver and silver-based electrical contact materials, although many brands, but summarized, can be divided into: ( 1 ) pure Ag; ( 2 ) silver alloy; 　　 ( 3 ) Silver--oxide; ( 4 ) Sintered alloy. The current contact and largest electrical contact materials are Ag , Ag-Au , AgPd , AgPt , AgMg , AgSn , AgCa , AgMn , AgCu , AgCe , AgCd , AgC , AgW , AgFe , AgNi, etc. and their respective multi-alloys and Ag- Me0 and other products.
Because China is rich in rare earth resources in the 1970s by the author of the first in the successful development of Ag-Ce0.5 alloy has been widely used Since then, a series of rare earth-containing silver-based electrical contact materials have been developed in China.
　　 Ag-Cd0 medium-load electrical contact material is the most representative of the material, due to the toxic Cd, thus developing a range of other Ag- oxide materials, until now there are still people Notes developers Ag-SnO2 material (including domestic oxidation, melting original Bit reset method, hot press sintering reaction method, mechanical alloying reaction method, etc.).
The reduction method (including electroplating) to prepare electrical contact materials is a key technology for silver-saving, that is, silver and silver alloys are used in key parts of electrical contact.
　　 Composite material
Silver composites are new materials that are combined by a composite process. It can retain Ag and the substrate and the main features, and can obtain the properties that the original components do not have the combined effect, complement each other, take care of each other, and use silver in key parts. It is an important silver-saving technology, silver. Composite materials have become a large class of advanced materials in modern times.
Industrial applications of silver-containing composite materials fall into two main categories: ( 1 ) composite materials of silver and silver alloys with other metal alloys (including surface complex, inlay complex, rivet complex, cladding, etc.); ( 2 ) silver-based Metal matrix composites (such as Ag-Mey0x , Ag-C fibers, sintered composites of non -interfused elements).
The first type of composite materials are silver / copper , silver / brass, silver iridium / copper, silver iridium / brass, silver iridium / zinc white copper, silver copper nickel / tin bronze, silver copper / brass, silver copper / tin bronze. , silver platinum / tin bronze, silver palladium / nickel silver, silver-copper / copper-tin-nickel, silver-copper / copper iron, silver, copper / aluminum, copper, cobalt, zinc, silver and copper / copper-aluminum-nickel-zinc, silver and copper / iron copper and aluminum, silver-copper / copper chromium zirconium, magnesium, silver, zirconium, cerium / iron nickel-copper-aluminum titanium, silver, zirconium, cerium / nickel silver, gadolinium, gold, silver nickel / copper, gold, silver zinc / nickel beryllium bronze, gold / silver / copper, gold / Silver gold nickel / copper nickel, gold / silver gold nickel / copper nickel and the like.
The second type of composite materials are Ag-Cd0, Ag-Sn0 2 , Ag-Zn0 2, Ag-Fe, Ag-Ni, Ag-W, Ag-C, Ag- dielectric ceramic materials such as ceramic.
From the perspective of silver-saving technology, silver composite materials are a new class of materials with great development prospects.
　　 Silver alloy solder
Among silver industrial alloys, a large category of silver-based brazing alloys has a wide range of applications and is widely used in various steel, stainless steel, non-ferrous metals, etc.; silver-based brazing fillers for special dosing components can also be used for welding. Tungsten, carbide, diamond , ceramic, carbon and glass. The problems in welding (such as titanium and gold, dispersion strengthened alloys and hardness alloys) can be solved by brazing technology, such as welding of ceramic components Si 3 N 4 , Zr0 2 and the like. It is easy to weld ceramics with a special silver brazing alloy without first metalizing the material. [next]
The traditional Ag-Cu welding alloy series are: Ag-Cu , Ag-Cu-Sn-In , Ag-Cu-Zn , Ag-Cu-Zn-Cd , Ag-Cu-Zn-Sn-In , Ag-Cu- Zn-Cd-Ni-Mn-In; Ag-Cu-Zn-In-Mn-Ni , Ag-Cu-Zn-In-Ni , Ag-Cu-In-Sn-P, and the like. Among them, Ag-Cu28 is the largest amount of electric vacuum solder.
In addition, Ag is widely used as an additive in Au alloy solders and Cu alloy solders. Au and Ag can be infinitely intertwined in both liquid and solid state, and the liquidus and the phase line have a narrow temperature range and can be used as a solder. Ag contained in an amount of 20 to 40% of Au-Ag alloy solder melting temperature (liquidus temperature) is between 950 ~ 1050 ℃, having excellent electrical conductivity, thermal conductivity and corrosion resistance. Au-Ag-Cu solder alloys have a wide range of composition, with Ag content ranging from 1 to 35 % and melting point (solidus temperature) between 780 °C and ～
The development direction of solder alloys is mainly to remove environmentally harmful elements from solder, to save precious metals and to provide solder alloys for special applications.
   Silver paste
With the rapid development of the electronics industry, silver paste is the basic material for manufacturing and developing electronic components, thick film hybrid circuits and touch components. Since the 1980s , due to the rise of surface mount technology ( SMT ), multi-layer thick film technology Has developed into the mainstream of hybrid microelectronics technology, touch components stand out, making silver paste into a wide variety of electronic paste, A wide range of products. At present, the demand for world slurry is more than 4,000 tons, and the output value is about 10 billion US dollars.
China's slurry development began in the 1960s . At that time, it mainly developed some foreign military banned export slurry. In the late 1980s, reform and opening up introduced many production knots from abroad, which brought challenges to the production of slurry. Sexual opportunities. The silver pastes that have been developed include: car glass hot wire silver paste, vacuum fluorescent display silver paste, solid tantalum capacitor special silver paste, semiconductor ceramic capacitor special silver paste, varistor silver conductor paste, piezoelectric buzzer Silver paste, silver conductive paste suitable for bonding metal and non-metal, silver paste for low temperature curing, medium temperature silver paste for thermistor with positive temperature coefficient, piezoelectric ceramic resonator, filter High-temperature silver paste in the field of devices, etc., back electrode silver paste and silver aluminum paste for single crystal silicon or polycrystalline silicon solar cells, silver palladium paste for thick film hybrid integrated circuit multilayer wiring and component electrodes, used as a film Polymer pastes in the field of switches and the like.
With China's accession to the WTO , foreign electronics companies have continually moved into China, Taiwan's electronics industry has also flocked to the mainland, and the required silver paste is still expanding. In this kind of symphonic competition, the domestic quality of silver paste and silver paste production We must work hard to solve mass production, stable performance, high quality, moderate price, and complete varieties.
   Energy industry silver
( 1 ) Silver-zinc battery. Among the chemical power sources, there are silver- cadmium batteries, silver-iron batteries, silver-magnesium batteries, and silver-zinc batteries. At present, the main application is a silver-zinc battery, that is, a zinc-silver oxide battery. Such a battery uses Ag 2 O or AgO as a positive electrode, zinc as a negative electrode, and potassium hydroxide as an electrolyte. In the 1990s, the silver - zinc battery production, the Bank of America annual consumption of about 40 tons, the estimated annual consumption of silver in the world more than 100 tons of silver - zinc batteries in aircraft, submarines, buoys, missiles, space vehicles And the use of ground electronic instruments and other special occasions, always maintain a long-lasting situation.
( 2 ) The fuel cell. The silver-catalyzed cathode for the 肼-air fuel cell is impregnated with a nitric acid solution and then processed to form a silver / activated carbon + polytetrafluoroethylene catalytic electrode. Among the solid oxide electric zinc batteries, Ag-(La0.7Sr0.3)Co0 3 and Ag-(La0.7Sr0.3)MnO 3 cermet films are available air electrode materials for SOFC .
( 3 ) Fast ion conductor. Fast ion conductors are a class of solid ion conductors that are comparable in conductivity to liquid electrolytes or molten salts, also known as solid electrolytes. The main silver ion conductors are α-AgI and RbAg.
( 4 ) The use of solar energy. The high reflectivity of silver can be used as a solar concentrating mirror. Silver paste, silver aluminum paste, etc. for solar cells.
The main application areas and development status of silver (1)
Abstract: The main fields of application are reviewed silver :( 1) of photosensitive material; (2) decorative materials; (3) contacting the material; (4) a composite material; (5) a silver alloy solder; (6) silver; (7 Silver for energy industry; ( 8 ) application of silver in catalysts; ( 9 ) silver in medicine Application; ( 10 ) Silver series antibacterial materials. The research and development status of silver in these main application fields is introduced. 950 °C . Solder alloy with a copper Cu-Ag-P, Cu- P-Ag-Sn, the liquidus temperature is between 925 ~ 683 ℃; No hormone added Ag solder alloy with the gold used in jewelry often color K. Gold alloy solders include Au-Ag-Cu (Zn , Sn , In) , Au-Ag-Ge-Si , etc. Platinum K- gold alloy solders add bleach to the Au-Ag-Cu system and adjust the melting point and improve The composition of the solder is non-volatile. 4 L 5 , Ag 2 O , Ag 2 SeO 4 , Ag 2 Mo0 4 , AgPO 3 and AgI-Ag 2 0-Se0 3 -Me0 3 , AgI-Ag 2 0-Mo0 3 and other fast ion conductive glasses, can be used for high energy density chemistry Power supply, relatively mature silver iodine battery is Ag/RbAg 4 L 5 /RbI3-C and so on.