What Is Abrasive Machining?

Abrasives are sharp, hard materials used to grind softer material surfaces. There are two types of abrasives, natural and artificial. According to the hardness classification, there are two categories of super-hard abrasives and ordinary abrasives. Abrasives range from softer household detergents, gem abrasives to the hardest material diamond. Abrasives are essential materials for every precision product. Many natural abrasives have been replaced by artificial abrasives. With the exception of diamond, the properties of natural abrasives are not very stable, but they still have their use value. Diamond is the abrasive with the highest hardness, mainly produced in South Africa, accounting for 95% of the world's total output, and the rest are Brazil, Australia, Guyana and Venezuela. Industrial diamonds range from off-white to black. After grinding, they can be made into grinding wheels, abrasive belts, polishing wheels and grinding powder.

Abrasive

Abrasives are sharp, hard materials used to

natural

Since the 1970s,

One of the important properties of the abrasive is its hardness. It must be harder than the material to be processed. Mohs hardness testers are commonly used to determine the hardness of various abrasives. Another important property of abrasives is toughness or bulk strength. Can change the mixing amount, purity, particle size and

Artificial abrasive products are mainly divided into

Super hard

Abrasive size

The particle size of the abrasive refers to the particle size of the abrasive. Abrasives can be divided into four groups according to their particle size: abrasive grains, abrasive powders, fine powders and ultrafine powders. Among them, the grain size numbers of the two groups of abrasive grains and powders are expressed by the number of meshes on the screen length per inch, and the mark is added with a "#" symbol in the upper right corner of the grain size number. For example, 240 # means that there are 240 holes in the length of each inch of the screen. The larger the value of the particle size number, the smaller the abrasive particles. The particle size numbers of the two groups of abrasives, micronized powder and ultrafine powder, are expressed by the actual size of the particles, and the mark is added by a letter "W" in front of the particle size number. Sometimes it can also be folded into a mesh number. For example, W20 indicates that the actual size of the abrasive particles is between 20m and 14m, which is 500 #.

There are coarse, medium and fine particles in the particle size of various abrasives. Medium grain is the basic particle size in the grinding powder, and it is the main factor that determines the grinding ability of the abrasive. It accounts for a large proportion in the particle size composition. Practice has proved that the grinding capacity of the grinding powder after centrifugal separation will be increased by 20% compared to that before the separation. Fine particles play a small role in grinding. In addition to detrimental to the quality of the workpiece, the particle size will also reduce the grinding efficiency. The number of particles should be minimized in the particle size composition. Therefore, in terms of grinding efficiency and work quality, the particles of the abrasive are required to be uniform. The abrasive grain group with a particle size of 12 # ~ 80 # has a larger particle size and is not suitable for abrasives for grinding processing.

Abrasive hardness

The hardness of the abrasive refers to the ability of the abrasive surface to resist local external effects, while the hardness of the abrasive tool (such as oil stone) is the firmness of the adhesive bonded abrasive under external force. It is one of the basic characteristics of the abrasive. The grinding process is realized by using the hardness difference between the abrasive and the workpiece. The higher the hardness of the abrasive, the stronger its cutting ability.

Abrasive strength

The strength of the abrasive refers to the firmness of the abrasive itself. That is, when the abrasive blade is relatively sharp, it can withstand the applied pressure without being broken. Abrasives with poor strength have fast pulverization of abrasive grains, low cutting capacity, and short service life. This requires that in addition to higher hardness, the abrasive particles should also have sufficient strength to perform the grinding process better.