Basic knowledge of abrasives

Abrasives and grinding tools play a very important role in industrial production. Today, we will bring you some related knowledge about abrasives and grinding tools! Ordinary abrasive bonded grinding tool is a tool that solidifies ordinary abrasive into a certain shape and has a certain strength by a binder. Generally composed of abrasives, binders, and pores, these three parts are often referred to as the three elements of bonded grinding tools.

Abrasives play a cutting role in grinding tools. Adhesive is a material that solidifies loose abrasives into grinding tools, and there are two types: inorganic and organic. Inorganic binders include ceramics, rhodochrosite, and sodium silicate; Organic materials include resin, rubber, and insect glue. The most commonly used ones are ceramic, resin, and rubber binders. Pores play a role in containing and removing debris during grinding, and can accommodate coolant, which helps dissipate grinding heat. To meet certain special processing requirements, certain fillers such as sulfur and paraffin can also be impregnated into the pores to improve the performance of the grinding tool.

This filler is also known as the fourth element of grinding tools. The items that represent the characteristics of ordinary abrasive bonded abrasives include: shape, size abrasive, particle size, hardness, microstructure, backing, backing adhesive, and binder.

The hardness of a grinding tool refers to the ease with which abrasive particles detach from the surface of the tool under external force, reflecting the strength of the binder holding the abrasive particles.

The hardness of the grinding tool mainly depends on the amount of binder added and the density of the grinding tool. If the abrasive particles are easily detached, it indicates that the hardness of the grinding tool is low; On the contrary, it indicates high hardness. The hardness grades are generally divided into seven levels: ultra soft, soft, medium soft, medium, medium hard, hard, and ultra hard, and several sub levels can be further subdivided from these grades. The commonly used methods for determining the hardness of grinding tools include the hand cone method, mechanical cone method, Rockwell hardness tester method, and sandblasting hardness tester method. The hardness of the grinding tool corresponds to its dynamic elastic modulus, which is beneficial for using the audio method to determine the dynamic elastic modulus of the grinding tool to represent its hardness. In grinding processing, if the material hardness of the workpiece being ground is high, a lower hardness grinding tool is generally selected; On the contrary, choose grinding tools with high hardness.