The hottest thing about abrasive

Everything about abrasive

selecting the best grinding wheel for a job forces the workshop to match the basic components of the grinding wheel - the characteristics of its abrasive and bonding system with the application requirements. Bonded abrasives, such as grinding wheels, consist of particles bound together by fixatives. Coated abrasives, such as those used on belt, disc, roller, plate and vane grinding wheel products, consist of abrasive particles stacked on a cloth or paper substrate. The classification of abrasives and bonding materials and their basic characteristics are quite simple. However, manufacturers mix many patented additives and fillers, which give these materials unique characteristics, which must be considered when meeting the application performance and finishing requirements

the types of abrasive components include alumina, silicon carbide, ceramic abrasive particles and superhard abrasives - Diamond and cubic boron nitride (CBN)

alumina

alumina is composed of pure formed particles and is very hard in its lowest refined form. During the melting period of alumina production, the crystal structure and its chemical properties can be controlled, which enables manufacturers to produce a series of products with different properties. Alumina can be made into many kinds of products, and its wide use makes it the most widely used abrasive

white corundum is softer and more brittle than other abrasives. It has high chemical purity (more than 99% Al2O3), which gives it sharp, low temperature and fast cutting ability. White corundum can maintain its shape well. It is used for grinding heat sensitive alloys. These applications take advantage of its brittleness and the fact that steel pipes and forged steels do not produce high temperatures during cutting. Such abrasive particles are also used to grind heat-treated tool steels, high-speed steels, and internal grinding wheels

chromic alumina is a kind of pink abrasive, which is used in grinding applications requiring a hardness slightly greater than that of white corundum. The chromium oxide composition of the abrasive improves its grinding ability. Although chromic alumina has brittleness and is used in low-temperature cutting, it shows strong shape retention characteristics. It is used for precision and large surface grinding on cemented carbide steel and professional grinding in tool room

brown corundum contains 2% to 4% titanium oxide (TiO2) to improve hardness. (titanium oxide is also called titanium dioxide.) It is the most widely used abrasive. It is used for grinding materials with high tensile strength, as well as for rough grinding, deburring and deburring, as well as cutting low-alloy and ferrous materials

low titanium oxide brown corundum contains 1% to 2% titanium oxide (tioo2) for bonding or coating applications, which are slightly harder than white corundum abrasives. Reducing the content of titanium dioxide will reduce the strength of the abrasive, but enhance its brittleness

zirconium aluminum composite oxide is the hardest alumina based abrasive, which is used for bonding, coating and sandblasting applications requiring extra hard abrasive

ceramic alumina is a small, non molten, ceramic compound. It is very hard and pure, and can produce products with completely consistent quality. It has excellent durability and cutting speed, and does not produce too much heat. It is used in applications where high cutting rate and long service life are required. It can be used to make resin and ceramic blades and grinding wheels. Ceramic alumina is particularly excellent in the fine grinding and finishing applications of steel and alloy that are difficult to grind

high chromium alumina is a ruby colored molten abrasive without titanium dioxide. It is made by melting high-purity calcined alumina and chromium oxide. It is a brittle abrasive, slightly harder than white corundum, and it has good angle retention characteristics required for fine grinding

silicon carbide

silicon carbide is a hard, sharp abrasive with super hardness. However, due to its brittleness, it breaks faster than alumina under heavy load

black silicon carbide is a semi brittle, medium density abrasive. It is used for manufacturing resin and ceramic blades and grinding wheels, and for grinding hard or brittle materials, such as cast steel, ceramics and glass. It is also used for grinding ductile non-ferrous metals with low tensile strength

green silicon carbide is the highest purity silicon carbide. It is a brittle, medium density abrasive used for ceramic and bonded blades and grinding wheels. It is widely used in grinding hard and brittle materials, such as cemented carbide, which requires fast and cold cutting

silicon carbide grinding wheel has hard and sharp abrasive particles

superhard abrasive

diamond and cubic boron nitride - superhard abrasive - rarely wear before the binder fails. Both natural and man-made diamonds are used as abrasives. The diamond family includes single crystal, polycrystalline, natural and ultra blasted diamonds. Boron nitride is man-made and has no natural analogues. It exists in the form of cubic crystal and polycrystalline

diamond is the hardest material known. However, it has limitations in grinding applications. The graphitization effect occurs when the temperature exceeds 1, 220 ° f (660 ℃), and the chemical reaction between the two forms of carbon occurs when diamond is used to grind carbon steel, which reduces the superhard abrasive properties of diamond. As a metal cutting or forming tool, diamond is the most effective in continuously improving the original products in automatic grinding and fine grinding of tungsten carbide, in processing the glass and porcelain parts of hip prosthesis and denture, and in processing carbide and glass processing in wire drawing. Resin bonded diamond products have mild to fast cutting characteristics. Ceramic bonded diamond wheel is more brittle than resin bonded diamond wheel, but the former is more free to cut at the same metal cutting rate. Metal bonded diamond wheels are used in heavy applications, such as cutting wheels that require high mechanical strength

cubic boron nitride (CBN) is second only to diamond in hardness and better than diamond abrasive in thermal stability. It is effective when the temperature reaches 3632 ° f (2000 ℃). Applications of CBN include grinding hard ferrous metals, cast steel, nickel and cobalt based alloys. In the field of automotive applications, it is an abrasive used for grinding chilled cast iron crankshaft or 1050 steel camshaft

in recent years, more varieties of CBN abrasive particles have been used for fine grinding. Its shape is accurately controlled during manufacturing, with enhanced thermal stability control and electromechanical rotation characterization. The challenge for wheel manufacturers is to develop bonding systems that take advantage of the increasing hardness of new abrasive particles. Because the abrasive particles become harder, they need to establish a stronger and more flexible binder for macro-control and market conditioning mechanism to bring economic benefits

these new CBN abrasive particles and a new glass bonding technology combined with high-strength glass or glass ceramic bonding system maximize the strength, hardness and wear resistance. R & D engineers worked with machine tool manufacturers to test process parameters to optimize the grinding cycle, and reported that they had achieved the desired economic benefits in large-scale, ultra precision inner and outer circle grinding of ferrous materials, including cast iron, steel and high nickel alloy. This new generation of ceramic CBN grinding wheels can be used to produce automotive camshafts, crankshafts and fuel injectors, as well as form grinding products. For example, the blades of a jet engine

it has been reported that the service life of grinding wheels is more than twice that of grinding wheels made with standard bonding systems in applications using new bonding platforms and high-quality abrasives

diamond wheel is suitable for grinding cemented carbide,

CBN wheel is suitable for grinding high-speed steel tools

What does it mean

brittle abrasive particles are easy to crack under impact. When in contact with the workpiece, the brittle grinding wheel has continuously exposed new cutting crystals, which makes it the fastest cutting abrasive

semi brittle abrasive grains are not as easy to crack as brittle abrasive grains, which means that the service life of abrasive grains during grinding is longer. However, semi brittle abrasive grains are not as easy to cut as brittle abrasive grains

make abrasive particles gather together

bonding materials make abrasive particles gather into grinding wheels, and they have no cutting ability

the skill of manufacturing grinding wheel is about balancing the amount of abrasive with the amount of bonding material and porosity to obtain the desired cutting tool characteristics

ceramic bond is very hard and brittle. Typically there are glass and ceramic binders. They cut materials at a high rate and are not affected by water, acid, oil or temperature changes

the resin bond is firm, wear-resistant and elastic. It is more impact resistant than ceramic bond and can withstand heavy load work. They are usually used for grinding work. This kind of binder is used for grinding wheels designed for rapid grinding and finishing. It also works well on stainless steel, brass, bronze and aluminum

rubber drying agent is used for grinding wheels that need to be engaged in high-quality finishing, such as grinding bearing races

treatment of improving performance

use some materials to treat bonded abrasive. Fill the pores of abrasive to reduce load, help cutting, improve the service life of grinding wheel, and lubricate cutting effect

sulfur treatment improves the cutting effect, but requires low-temperature processing. Abrasive treated with sulfur should be used together with coolant

resin treatment hardens the abrasive and enhances lubrication to help cutting

wax treatment is common in grinding brass or aluminum because it reduces load and lubricates cutting action. (end)