Classification and development of the hottest abra

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Classification and development of abrasive tools

abrasive tools are tools used for grinding, grinding and polishing. The elastic modulus of the material is not less than 200gp. Most of the abrasives are artificial abrasives made of abrasives and binders, and also natural abrasives directly processed from natural minerals and rocks. In addition to being widely used in machinery manufacturing and other metal processing industries, abrasives are also used in grain processing, paper industry and the processing of non-metallic materials such as ceramics, glass, stone, plastic, rubber and wood

during the use of the abrasive tool, when the abrasive particles are blunt, the abrasive particles will fall off from the abrasive tool locally or completely due to the partial fragmentation of the abrasive particles themselves or the fracture of the bond, and the abrasive on the working surface of the abrasive tool will continue to appear new cutting edges or expose new sharp abrasive particles, so that the abrasive tool can maintain its cutting performance for a certain period of time

as early as the Neolithic age, people began to use natural grindstones to process stone knives, axes, bone tools, horn tools, tooth tools and other tools; In 1872, the ceramic grinding wheel made of natural abrasive and clay appeared in the United States; Around 1900, artificial abrasives came out, and various abrasive tools made of artificial abrasives came into being one after another, creating conditions for the rapid development of grinding and grinding machines. Solution: after ensuring the processing quality of hydraulic components of universal testing machine, the proportion of natural abrasives in abrasives gradually decreased

Abrasives can be divided into natural abrasives and artificial abrasives according to their raw material sources. The only natural abrasive tools commonly used in the machinery industry are oilstones. According to the basic shape and structural characteristics, man-made Abrasives can be divided into five categories: grinding wheel, grinding head, oilstone, sand tile (collectively referred to as consolidation wet molding technology abrasives on the basis of the recovery of the international market: plastic extruder regains confidence) and coated abrasives

consolidated Abrasives can be divided into ordinary abrasive consolidated abrasives and superhard abrasive consolidated Abrasives according to the different abrasives used. The former is made of common abrasives such as corundum and silicon carbide, while the latter is made of superhard abrasives such as diamond and cubic boron nitride

ordinary abrasive consolidation abrasives are abrasives with certain strength, which are made of ordinary abrasive consolidated into a certain shape by binding agent. It is generally composed of abrasive, binder and pore, which are often called the three elements of consolidated abrasive tools

abrasive plays a cutting role in abrasive tools. Binding agent is the material that consolidates the loose abrasive into abrasive tools. It has two types: inorganic and organic. Inorganic binders include ceramics, siderite and sodium silicate; Organic ones include resin, rubber and shellac. The most commonly used are ceramics, resins and rubber binders

the air hole plays the role of chip holding and chip removal during grinding, and can hold the coolant, which is helpful to the dissipation of grinding heat. In order to meet some special processing requirements, the pores can also be impregnated with some fillers, such as sulfur and paraffin, to improve the service performance of abrasive tools. This filler is also known as the fourth element of abrasive tools

the hardness of abrasive tools mainly depends on the amount of binder added and the density of abrasive tools. The abrasive particles that are easy to fall off indicate that the hardness of abrasive tools is low; Otherwise, it means high hardness. Hardness levels are generally divided into seven levels: super soft, soft, medium soft, medium hard, hard and super hard. From these levels, several sub levels can be subdivided. The commonly used methods for measuring the hardness of abrasive tools are hand cone method, mechanical cone method, Rockwell hardness tester method and sand blasting hardness tester method

there is a corresponding relationship between the hardness of abrasive tools and their dynamic elastic modulus, which is conducive to measuring the dynamic elastic modulus of abrasive tools by audio method to express the hardness of abrasive tools. In the grinding process, if the material hardness of the workpiece to be ground is high, the abrasive tool with low hardness is generally selected; On the contrary, select abrasive tools with high hardness

Abrasives can be roughly divided into three types: compact, medium and loose. Each category can be subdivided and distinguished by organization number. The larger the organization number of the abrasive, the smaller the volume percentage of the abrasive in the abrasive, and the wider the gap between the abrasive particles, indicating the looser the organization. Conversely, the smaller the organization number, the tighter the organization. The abrasive tools with loose structure are not easy to passivate when used, and have less heat during grinding, which can reduce the heating deformation and burn of the workpiece. The abrasive grains of abrasive tools with tight structure are not easy to fall off, which is conducive to maintaining the geometric shape of abrasive tools. The structure of abrasive tools is only controlled according to the abrasive tool formula during manufacturing, and generally is not measured. (end)

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