Grinding wheel is the main tool for grinding, suitable for grinding high-hardness steel such as high-speed steel, high-carbon steel, hardened steel, and alloy steel. It is a porous body composed of abrasives and binders. The abrasives, binders and holes are the three basic elements of the grinding wheel. According to the structure of the machine tool and the needs of grinding processing, the grinding wheel is divided into flat grinding wheel and double concave grinding wheel. Double inclined grinding wheel, cylindrical grinding wheel, disc grinding wheel and bowl grinding wheel. So how to choose the hardness of white corundum, brown corundum and other grinding wheels?
Grinding wheels are made in different shapes and sizes. Due to the differences in abrasives, binders and wheel manufacturing processes, the characteristics of grinding wheels can vary greatly, which has a significant impact on the precision, roughness and production efficiency of the grinding process. Therefore, the appropriate grinding wheel must be selected according to the specific situation.
The characteristics of a grinding wheel are determined by factors such as abrasive, particle size, hardness, binder, shape and size. We have already covered the issues of abrasive, particle size and binder selection. Commonly used abrasives are white corundum, brown corundum, green silicon carbide, black silicon carbide, etc. The selection of grinding wheel hardness is mainly introduced here.
The hardness of the grinding wheel refers to the difficulty of the abrasive particles on the surface of the grinding wheel falling off under the action of grinding force. The hardness of the grinding wheel is soft, which means that the abrasive grains of the grinding wheel are easy to fall off, and the hardness of the grinding wheel is hard, which means that the abrasive grains of the grinding wheel are not easy to fall off. Wheel hardness and abrasive hardness are two different concepts. The same abrasive can be made into grinding wheels with different hardness, which mainly depends on the nature and dosage of the binder and the manufacturing process of the grinding wheel. The significant difference between grinding and cutting is that the grinding wheel has a "self-grinding" function. Choosing the hardness of the grinding wheel is actually choosing the self-grinding of the grinding wheel. Hopefully the abrasive doesn't come off prematurely or become dull.
The general principle for selecting the hardness of the grinding wheel is: when processing soft metals, in order to prevent the abrasive from falling off prematurely, a hard wheel is selected. When processing hard metals, in order to make the blunt surface abrasive particles fall off in time and expose new abrasive particles with sharp edges (ie, self-abrasive particles), a soft grinding wheel is selected. The former is because when grinding soft materials, the working abrasive of the grinding wheel wears slowly and does not need to fall off prematurely; the latter is because when grinding hard materials, the working abrasive of the grinding wheel wears faster and needs to be updated quickly. In precision grinding, in order to ensure the grinding accuracy and roughness, a slightly harder grinding wheel should be used. The workpiece material has poor thermal conductivity and is prone to burns and cracks (such as grinding cemented carbide, etc.). The choice of grinding wheel should be soft.
The above is a detailed introduction to how to choose the hardness of white corundum, brown corundum and other grinding wheels. I hope you can choose easily!
