Grinding is a method of cutting a workpiece using a grinding wheel as a cutting tool on a grinder. The characteristics of this method are:
(1) Because the grinding wheel has high hardness and heat resistance, it can grind and process materials with high hardness, such as hardened steel, cemented carbide, etc.
(2) The characteristics of the grinding wheel and the grinding machine determine that the grinding process can perform uniform micro-cutting, generally ap = 0.001 ～ 0.005mm; the grinding speed is very high, generally up to v = 30 ～ 50m / s; the rigidity of the grinding machine is good; hydraulic pressure is used Transmission, so grinding can economically obtain high machining accuracy (IT6 to IT5) and small surface roughness (Ra = 0.8 to 0.2 μm). Grinding is one of the main methods of part finishing.
(3) Vigorous friction makes the very high temperature in the grinding zone . Causes stress and deformation of the workpiece, and even burns the surface of the workpiece. Therefore, a large amount of coolant must be injected during grinding to reduce the grinding temperature. The coolant acts as chip removal and lubrication.
(4) The radial force during grinding is very large. This will cause the elastic concession of the machine-grind-workpiece system, making the actual cutting depth smaller than the nominal cutting depth. Therefore, when grinding is about to be completed, light grinding should be performed without feeding to eliminate errors.
(5) After the abrasive grain are dulled, the grinding force also increases, causing the abrasive grains to break or fall off, and the sharp cutting edge is exposed again. This characteristic is called "self-sharpness". Self-sharpness enables grinding to be performed normally within a certain period of time, but after a certain working time, manual trimming should be performed to prevent the increase of grinding force from causing vibration, noise and damage to the surface quality of the workpiece.