Abrasive type

   Mostly with hard abrasive non-metallic materials, with natural and artificial two categories.
    Natural abrasives ore through direct use of natural selection, crushing, grading, or other abrasive made ​​ cutting tools . There are natural emery, natural corundum, natural garnet and diamond and so on. Table 1 describes the characteristics of this type of abrasive and main uses. Natural abrasives by natural conditions due to resource constraints, it is difficult to artificially control, so compared with artificial abrasives has been relegated to a secondary position.
   Artificial abrasive artificially refining or synthetic abrasives. Wider application of corundum,  synthetic diamond , boron carbide, synthetic diamond and cubic boron nitride. Table 2 lists their main purpose. Diamond and cubic boron nitride is often called the super abrasive or superhard materials, and corundum, silicon carbide, then it is called ordinary abrasive. Additionally, in some grinding and polishing, as well as with the so-called "soft abrasives," such as chromium oxide, iron oxide and cerium oxide. Artificial corundum and silicon carbide abrasive due to wear, corrosion, or in the optical, electrical, thermal, etc. have different characteristics, in addition to used as an abrasive, there are many other uses, such as high-grade refractory, electric materials, high temperature semiconductor materials and engineering construction materials.