Diamond grinding wheels process cemented carbide tools

Cemented carbide uses metal carbides such as tungsten carbide and titanium carbide as the hard phase, and cobalt and other metals as the binder. It is made through the method of powder metallurgy. It has high hardness (up to HRA89-93, microscopic Hardness 1300-1800N/mm2), lower thermal conductivity (16.75-79.55W/m•K), lower bending strength (3.0-4.5GPa) and larger elastic wear (540-650GPa). It is a hard and brittle material at normal temperature. It means that it has different grinding requirements from steel parts and other materials. In the past, green silicon carbide grinding wheels were often used for cemented carbide, but because the hardness of silicon carbide abrasives was not high enough (microhardness 32000 -34000N/mm2), the abrasives are easy to wear and blunt when grinding cemented carbide. It causes the increase of grinding force and high grinding temperature, resulting in defects such as cracks on the surface of the tool. At the same time, the abrasive of silicon carbide grinding wheel is too fast, and the shape of the grinding wheel is not easy to maintain so that the tool size is unstable.

As the diamond abrasive has high hardness, sharp cutting edges and high wear resistance, diamond grinding wheels have basically replaced silicon carbide grinding wheels as the first choice for grinding cemented carbide in recent years. The main characteristic parameters of diamond grinding wheels are: 1.diamond grit, indicating the average size of diamond abrasive grains, commonly used diamond grit is D64, D46, D35 (FEPA standard), etc.; 2.Concentration, refers to the diamond content contained in each cubic centimeter of the abrasive layer, the usual concentration is C100, which means the diamond content is 4.4ct/cm3; 3.Binders, commonly used are metal bond (M), resin bond (B), ceramic bond (V); 4.shape, like flat grinding wheel, bowl grinding wheel, bevel grinding wheel, etc.; 5.Dimensions, for example, some manufacturers use the diamond grinding wheel model: 1A1-D100*T6*X5-D64C100 B means that the shape of the grinding wheel is flat grinding wheel, diameter 100mm, thickness 6mm, abrasive layer width 5mm, diamond size is D64, the concentration is C100, resin bond.