PCD tool must ensure good edge before processing workpiece, diamond grinding wheel grinding is the most widely used method. The higher the quality of the cutting edge, the finer the knife marks left at the boundary of the tool geometry reflection area of the workpiece surface, and the higher the surface finish of the workpiece. Because the edge is broken or extended easily cause tool wear or damage, reduce the tool life. Edge breakage is the key index of diamond cutting edge quality.
The grinding mechanism of PCD tool is as follows: the abrasive grains of diamond grinding wheel constantly impact PCD material, making the diamond on PCD have brittle breakage (including intra - crystal fine breakage, intergranular breakage and cleavage breakage), sliding wear and scratching; Thermochemistry is the oxidation or graphitization of diamond due to the high temperature generated during grinding. There are many factors affecting the cutting edge quality of PCD tools, such as the particle size of diamond powder in PCD composite pieces, types of diamond grinding wheels, equipment performance and fixture rigidity, etc.
1. Particle size of diamond powder
Under the same other conditions, the particle size of PCD diamond powder is positively correlated with the cutting edge breakage, that is, the larger the particle size is, the larger the cutting edge breakage is. At the same time, the edge breakage of the mixed particle size is smaller than that of the coarse particle size, but closer to that of the medium particle size, because the pure coarse particle size is filled with metal binder, while the mixed particle size consists of both binder and other fine particle size gradation between the coarse particles.
In the process of grinding, the abrasive grains of diamond of grinding wheel constantly impact the edge of PCD tool, and the plastic of PCD tool is poor, the edge will produce microscopic fracture edge. From the microscopic analysis, the diamond particles in PCD tool appear brittle fracture and collapse during extrusion and friction, and the size of the fracture formed by brittle fracture is positively correlated with the particle size of diamond powder, the larger the particle size, the greater the edge collapse. In addition, because of the fine round diamond abrasive hardness is lower than the medium and coarse particle of PCD diamond particles, abrasive score function is weak, but the fine wheel abrasive wear easily and congestion, high grinding temperature, brush and thermal chemistry dominant sliding, thus reduce or eliminate the brittle fracture appear larger crack, so the final formation of edge collapse is less than the particle size.
2. Types of diamond grinding wheel
The order of edge breakage is metal bond grinding wheel > vitrified bond grinding wheel > resin bond grinding wheel. When the grinding wheel particle size is larger than W10, the edge breakage value is sensitive to the grinding wheel particle size and increases with the increase of the grinding wheel particle size. When the grinding wheel particle size is less than W10, the edge breakage value is not sensitive to the grinding wheel particle size.
Metal bond diamond grinding wheel grinding grain broken occurred in the process of grinding to maintain state, sharp grinding, so as to realize the resin bond diamond grinding wheel surface will occur because of the heat deformation, appropriate USES low grinding speed, ceramic binder is composed of a variety of materials with pressure, grinding process of bond and diamond grits collective falls off easily, The PCD tool surface left pits.
MORESUPERHAD can supply quality PCD grinding wheel at very long life as well as fast cutting. We only choose the very strong synthetic diamond as the raw materials, we make sure not only the particle shape is round enough but also be with some sharp points, which can make sure we won’t lose the efficiency while we still want enough life from the wheels. So it will help you get fast , stable, much more PCD tools in unit time. Our 6A2 vitrified diamond grinding wheel Cylindrical grinding, surface grinding, regrinding PCD cutting tools, PCBN cutting tools, CVD tools, MCD tools, ceramic tools, cermet tools, milling cutter, reamer, drill, etc.
---EDITOR: Doris Hu
---POST: Doris Hu