Introduction Of Abrasive Tools

Abrasive tools are tools for grinding and polishing. Most of the abrasives are artificial abrasives made of abrasives and bonding agents. There are also natural abrasive tools directly processed from natural ore. In addition to being widely used in machinery manufacturing and other metal processing industries, abrasive tools are also used in the processing of non-metallic materials such as food processing, paper industry and ceramics, glass, stone, plastic, rubber, and wood. During the use of the abrasive tool, when the abrasive grains are blunt, the abrasive grains partially or completely fall off from the abrasive tool due to the partial fragmentation of the abrasive grains or the fracture of the bonding agent. The abrasives on the working surface of the abrasive tool continuously appear with new cutting edges, or constantly expose new sharp abrasive particles, so that the abrasive tool can maintain the cutting performance for a certain period of time.

This kind of self-sharpening of abrasive tools is an outstanding feature of abrasive tools compared with general cutting tools. As early as the Neolithic Age, humans have already used natural grindstones to process stone knives, stone axes, bone tools, angle tools and dental tools. In the 19th century, there appeared ceramic sand discs made of natural abrasives and clay in the United States. Around 1900, artificial abrasives came out, and various abrasive tools made of artificial abrasives were successively produced, which created conditions for the rapid development of grinding and grinders. Since then, the proportion of natural abrasive tools in abrasive tools has gradually decreased.

Abrasives are divided into natural abrasives and artificial abrasives according to their source of raw materials. The only natural abrasive tools commonly used in the machinery industry are oilstone. Artificial abrasive tools are classified according to their basic shapes and structural features. There are five types of abrasive discs, grinding heads, oilstones, and sand tiles, which are collectively referred to as consolidated abrasives and coated abrasives. In addition, it is customary to classify abrasives as a type of abrasive tool.

According to the different abrasives used, fixed abrasives can be divided into ordinary abrasives and super-hard abrasives. The former is made of ordinary abrasives such as corundum and silicon carbide, and the latter is made of super-hard abrasives such as diamond and cubic boron nitride. In addition, there are some special varieties, such as sintered corundum abrasive tools.

Ordinary abrasive-consolidated abrasive tools are abrasive tools in which ordinary abrasives are consolidated into a certain shape by a bonding agent and have a certain strength. It is generally composed of abrasives, bonding agents and pores. These three parts are often referred to as the three elements of a consolidated abrasive tool. Abrasives play a cutting role in abrasive tools. Binders are materials that consolidate loose abrasives into abrasive tools, and there are two types that are inorganic and organic. Inorganic binders include ceramics, magnesia and sodium silicate. Organic ones include resin, rubber and shellac. Among these, the most commonly used are ceramic, resin and rubber bonding agents.

The pores play a role in holding and removing debris during grinding, and can contain coolant, which helps to dissipate the grinding heat. In order to meet some special processing requirements, some fillers, such as sulfur and paraffin, can also be impregnated in the pores to improve the performance of the abrasive tool. This filler is also known as the fourth element of abrasive tools.