Grinding is the cutting method of cutting materials with abrasive.
As diamond abrasive tools such as diamond grinding wheel are used as cutting tools, the grinding process has some remarkable characteristics compared with the common cutting process.
1. Irregular cutting edge
The shapes of abrasive grains are mostly octahedral, with different sizes and shapes, which are randomly distributed on the grinding wheel. After dressing the corundum grinding wheel, the grinding grains are often cut under the condition of a large negative front Angle (r0 is -65° to 80° on average), and the edge edge of the top Angle has a large blunt circle radius. When the abrasive particles are finely trimmed, some tiny cutting edges are produced, which are called micro edges.
2, the cutting thickness is thin
The cutting thickness is usually only a few microns, so the grinding can obtain higher accuracy and less roughness.
Because the abrasive particle has a certain edge blunt radius, the energy consumed by cutting the material per unit volume (called specific grinding energy) is larger, which is about 10 times more than that of milling.
3. High grinding speed
The grinding speed of diamond grinding wheel can reach 60m/s, which is more than 10 times of the cutting speed of ordinary tool.
At present, the grinding speed can be developed to 120m/s, and high metal removal rate can be obtained.
4. High grinding temperature
The diamond grinding wheel has a high grinding speed, short contact time between the grinding particle and the workpiece, and produces strong friction and sharp plastic deformation. The average temperature of the contact area between the diamond grinding wheel and the workpiece is generally 500-800℃, and the grinding point temperature of the grinding particle can be as high as 1000℃, and more than 80% of the heat will be transferred to the workpiece. Therefore, the processed surface is prone to thermal damage.
As can be seen from above, it is necessary to pay full attention to, properly apply and reasonably deal with the grinding characteristics and various influences brought by the grinding wheel in the grinding process