White corundum sand, white corundum powder, brown corundum and other abrasives are relatively common abrasives, especially white corundum powder, which is the first choice for polishing and grinding. It has the characteristics of single crystal, high hardness, good self-sharpening, and grinding and polishing performance. Advantages such as superiority have been used and promoted in various industries. So, how to choose when polishing?
Abrasive selection
Abrasive is the main body that plays a cutting role in the grinding process. It is directly responsible for the cutting work and is the fundamental factor for the grinding wheel to produce the grinding effect. The abrasive must be brown corundum produced by Xinli wear-resistant. Its products have high hardness, heat resistance, thermal stability and chemical stability, and should also have a certain toughness so that it can withstand a certain grinding force.
Abrasive selection principle
When grinding materials with higher tensile strength, use corundum abrasives with higher toughness. Grinding materials with low tensile strength to select brittle silicon carbide abrasives.
In addition to considering the tensile strength of the workpiece material, the hardness of the workpiece material is also the main selection basis when selecting abrasives. Generally speaking, the hardness of the abrasive should be 2-4 times higher than the hardness of the workpiece material. Otherwise, the abrasive grains with lower hardness will be quickly passivated during high-speed cutting and lose the cutting ability, which will make the wheel durability too low and affect the cutting. efficiency, and the processing quality cannot be guaranteed. Therefore, the higher the hardness of the workpiece material, the higher the hardness of the abrasive should be.
Selection of abrasive properties
Consideration should also be given to possible chemical reactions in the grinding process system. In the grinding contact area, abrasives, binders, workpiece materials, grinding fluids and air are prone to spontaneous chemical reactions under the catalytic action of grinding temperature and grinding force. When steel is used, the abrasive wear is faster than that of corundum abrasive when grinding steel. The main reason for this is the strong chemical reaction between the silicon carbide abrasive and the steel.
In addition, the thermal stability of the abrasive should also be considered when selecting an abrasive. When grinding some hard-to-grind materials, other accidents occur when the grinding zone is prone to generate higher temperatures.