Abrasives are tools for grinding, grinding and polishing. The stone is bright and smooth, which can't be separated from the work of grinding tools. Therefore, abrasive equipment is an important kind of equipment in stone industry.
The classification of abrasives and equipment in stone industry is complex. According to the source of raw materials, it can be divided into natural abrasives and artificial abrasives. Only whetstone is commonly used in mechanical industry. According to the basic shape and structural characteristics, artificial abrasives can be divided into five categories: grinding wheel, grinding head, oilstone, sand tile (collectively referred to as consolidated abrasive tools) and coated abrasives. In addition, it is customary to list Abrasives as a class of abrasives.
According to the different abrasives used, consolidated Abrasives can be divided into ordinary abrasive consolidated abrasives and superhard consolidated abrasives. The former is made of ordinary abrasives such as corundum and silicon carbide, while the latter is made of superhard abrasives such as diamond and cubic boron nitride.
The ordinary abrasive consolidation abrasive tool is a kind of abrasive tool which is consolidated into a certain shape and has a certain strength by the bond. It is generally composed of abrasives, binders and pores, which are often called the three elements of consolidated abrasives.
In general, the characteristics of ordinary abrasive bonded abrasives are: shape, size, abrasive, particle size, hardness, microstructure and binder. The commonly used methods for measuring the hardness of abrasive tools are hand cone method, mechanical cone method, Rockwell hardness tester method and sandblasting hardness tester method.
The main characteristics of abrasives include abrasive, particle size, hardness, microstructure and binder. The processing quality and production efficiency can be directly improved by selecting the appropriate products according to different applications.
Abrasive materials:
Abrasives used mainly include brown corundum, white corundum, black silicon carbide and green silicon carbide.
Brown corundum has high toughness and is suitable for grinding carbon steel, alloy steel, malleable cast iron, hard bronze and other materials with high tensile strength. Compared with brown corundum, white corundum has higher hardness and better cutting performance. It is suitable for fine grinding of quenched steel, high carbon steel and high-speed tools.
Black silicon carbide has high hardness, brittle and sharp, suitable for grinding and cutting materials with low tensile strength, such as cast iron, glass, ceramics, stone, refractory, etc.
The purity of green silicon carbide is higher than that of black silicon carbide. It is suitable for grinding hard alloy, optical glass, gem, agate and other hard and brittle materials.
Grain size: the choice of particle size mainly depends on the machining accuracy and production efficiency of the workpiece surface. Coarse and medium grain grinding tools are suitable for rough machining and semi finishing, while fine-grained grinding tools are used for finishing and superfinishing. The material with low hardness, high ductility and toughness should be processed with coarse-grained abrasive tools, while the materials with high hardness and brittleness should be processed with fine-grained abrasive tools.
Structure: the structure of abrasive tools refers to the volume ratio relationship among abrasive materials, binders and pores. Less abrasives and high porosity are called loose structure, and vice versa. The abrasive tools with compact structure are suitable for fine grinding, molding grinding and processing workpieces with small space and high surface finish requirements. The abrasive tools with medium structure are widely used in the grinding of general workpieces with allowance. The loose structure grinding tool is suitable for grinding large contact surfaces such as plane and inner circle, and grinding expansion sensitive workpiece and soft material workpiece.
Hardness: the strength at which the abrasives on the surface of an abrasive are held together by a bond. Or under the action of external force, the difficulty of falling off is called the hardness of abrasive tools.