2013-09-02 by seoer3
For different workpiece materials, different processing requirements, should use a different wheel. Even grinding the same workpiece material, different grades of grinding wheel grinding ratio may vary from 2 to 5 times, and therefore the appropriate choice of the wheel. Diamond grinding wheel is grinding carbide, optical glass, ceramics, stones and stone high hardness brittle non-metallic materials, the best coated abrasive . But the diamond at 700 ℃ ~ 800 ℃ easily when carbonation, so it is not suitable for grinding steel material. CBN is slightly inferior to the hardness of diamond, but it's good thermal stability (the ability of 1300 ℃ ~ 1400 ℃ high temperature), it does not like the diamond that will break down at high temperatures, ie, oxidation and graphite, with a large iron group elements chemically inert, high thermal conductivity (46 times corundum), with its production of wheel life long (corundum grinding wheels up to a hundredfold more than a few times), is an alternative corundum grinding wheel hardened steel, high speed tool steel, bearing steel , stainless steel, heat-resistant steel and titanium metal toughness, high hardness materials, the best abrasive. Grinding wheel with a binder resin, metal, ceramics, plating and brazing. Resin bonded grinding wheel is mainly used for measuring blade sharpening, grinding holes, cylindrical grinding and surface grinding; metal bonded grinding wheel for cutting, shaping optical curve grinder grinding, sharpening single-edged knives, grinding small drill spiral grooves, also applies to electrolytic grinding; vitrified grinding wheel of high efficiency, good shape retention and durability, easy dressing, grinding, long life, and because of vitrified itself has good chemical stability, heat, oil, acid erosion, can be adapted to a variety of grinding fluids, grinding, low cost, and thus has become efficient, high-precision grinding preferred abrasive; electroplated grinding wheel suitable for high speed grinding and forming mill, also suitable hole efficient grinding (wet) and use the jig grinder; brazed wheel suitable for ultra-high speed grinding. Should be noted that different grades of abrasives, because the manufacturing process is different, the crystal morphology, particle shape are different, and have different strength, thermal stability, and fragmentation characteristics, should be based on type of binding agent, grinding the workpiece material and the grinding means, Select a different abrasives. As for efficient, high-precision grinding of ceramic bonded grinding wheel, the choice of high strength and abrasive particle shape sharp, hard surface grinding production there metallization clothing (metal coating can play reinforcement toughened, heat shock mitigation as well as between the abrasive particles and the binder from the combined effect of the bridge can be improved wheel performance) and non-metallised coat two kinds, should be based on the binder type, workpiece material, both dry and wet conditions, such as different choices. Dry grinding is generally used copper coat; wet optional Nickel. Currently, metal plating by nickel, copper developed to titanium, tungsten alloy, nonmetal ceramics, etc., by a single coating developed to the composite coating, and has been developed to a fine powder coated abrasive coating. From hard abrasive wheel can not choose too low concentration and high concentration can bring high grinding ratio, 200% concentration of superabrasive grinding wheel is actually a kind of super abrasive grinding wheel as adjunct general, is generally not recommended Named use. Currently, high-speed and efficient grinding higher concentrations are used, vitrified CBN grinding wheel are made of a high concentration of high-density, vitrified CBN grinding wheel generally choose more than 125% concentration, such as import supporting ceramic CBN grinding wheels concentrations in general are 175% to 200%. Expressed wheel hardness grade of binder on the size of the abrasive gripping force. Wheel hardness uniformity and stability and hardness of the level of rational choice, is an important prerequisite to ensure the quality of grinding. Foreign grinding wheel generally 3 to 7 hardness levels to choose from, but China's production of superhard grinding wheel hardness level is not standard, GB6409 also does not provide the appropriate standards, so the quality is not guaranteed and inconvenience to users, urgent supplement and perfect.
2013-11-18 by seoer3
Ultrahigh pressure water jet technique using ordinary tap water can be pressurized to 250-400Mpa pressure , and then through the inner bore diameter of about 0.15-0.35mm jewel nozzle forming speed of about 800-1000m / s high speed jet, which is commonly known as water arrows , arrows that water has a high energy , can be used to cut soft base materials . If we add the right amount of water arrows coated abrasive can be used to cut almost all of the hard and soft materials . Adjust water jet pressure and flow , you can use it to clean a variety of objects, such as in addition to plastic , paint , rust , etc., we can also use high pressure autoclave technology , food preservation , and many other useful work for humanity . Waterjet cutting can be characterized in any of the materials disposable cutting arbitrary curves ( except water cutting other cutting methods will be outside the variety of materials restrictions ) ; cutting does not produce heat and harmful substances, materials non-thermal effects ( cold cuts ) , easy to cut unnecessary or secondary processing , safety, environmental protection , low cost , high speed , high efficiency, can be arbitrary curve cutting, convenient and flexible , and versatile. Water cutting is the most versatile method of cutting process . Water jet cutting and laser cutting relatively large laser cutting equipment investment is currently used mostly for thin steel plate , some non-metallic materials, cutting , cutting speed, high accuracy, but when laser cutting kerf marks Office will cause the arc and cause thermal effects ; addition to the laser cutting some undesirable materials , such as aluminum , copper and other metals, alloys, especially thick sheet metal cutting , the cutting surface is not satisfactory, or even can not be cut . There is now research on high-power laser generator is trying to solve the thick steel plate cutting , but the investment in equipment , maintenance and operating costs of consumption is also very impressive . Water cutting small investment, low operating costs, cutting wide range of materials , high efficiency, easy operation and maintenance .