Re-grinding PCD Tools

With the development of The Times, the requirements for cutting tools are also constantly improving, requiring longer tool life, higher processing quality, better cost performance, and many high precision superhard tools to meet the needs of aerospace, automotive, and other industrial fields of production to a large extent. Meanwhile, the emergence of new high-performance tool materials has greatly promoted the development of the aerospace and automotive industries.About the re-grinding PCD tools have also many points to note.

1. High quality cutting edge radius is the key to ensuring the performance of the tool

One of most critical factors affecting the quality of ultra-precision machining is the grinding quality of the pcd tool -- edge radius, which is related to chip deformation and minimum cutting thickness as well as the surface quality of the product, namely the surface roughness. For pcd and pcbn cutting tools, the smaller the radius of the cutting edge, the smaller the cutting thickness. If the cutting thickness is less than a specific limit, cutting is not usually working. Especially natural diamond tools, after fine grinding and super-fine grinding, can produce incredibly sharp cutting edges with a blunt radius of up to microns. With reasonable geometric and cutting parameters, ultra-precision machine tools can process ultra-precision parts. Because of the sharpened cutting edge and the friction coefficient between the diamond tool and the small workpiece material, obtaining a smoother workpiece surface is beneficial.

2. High-precision machine tool is an essential aspect of ensuring the quality of tool grinding

The precision of the machine tool has the most significant influence on the grinding quality of the super-hard tool, which is the main factor that determines the tool's service life and processing quality. Only in the high-precision machine tool can the super-hard tool be grinding qualified to meet the production needs.

For example, the RS15 high precision tool grinder produced by EWAG of Switzerland can be used to grind the PCD cutter, which can realize the mirror machining, Ra-min=0.007mm.

The rotary accuracy of the machine tool spindle, the vibration resistance of the system, the accuracy of feed motion, and the stiffness of the machine tool all have a direct effect on the surface roughness of the grinding tool edge through the variation of cutting depth ap and the variation of feed direction f. It is impossible for low-precision machine tools to produce low-roughness tools.

3.  Re-grinding of pcd tools

The grinding wheel used for grinding diamond tools is the diamond wheel, W40 diamond wheel for coarse grinding, W5-W20 diamond wheel for fine grinding, ceramic or metal binder with a concentration of 100 ~ 125, and silicon carbide grinding wheel for the dressing of grinding wheel.

Before grinding, firstly, test the balance of the grinding wheel. After installing the diamond grinding wheel on the flange plate, we correct the static balance on the balancing instrument. After meeting the requirements, we can operate the grinding wheel.

During grinding, the linear speed of the grinding wheel is 800 ~ 1000m/min, the swing speed of the table is 30 ~ 60 times /min, and the cutting fluid is water-soluble grinding fluid.

The front blade face should be polished before grinding pcd blades. Because the grinding blade has been polished during manufacturing, this process can be exempted. After fine grinding, 30 ~ 50 times the microscope should be used to confirm whether the edge of the small collapsed; Cutting non-ferrous metal blades does not need to carry out cutting edge passivation treatment, a sharp edge cutting effect is better.