With the development of high and new technologies, the manufacturing process of graphite materials has been continuously improved. High-speed graphite milling machine tools have emerged on the market. Graphite materials that can meet different processing needs are emerging in an endless stream. The graphite discharge performance of CNC EDM machine tools has also been comprehensively improved.
Graphite has high-temperature strength, low thermal expansion coefficient, good processability, and good thermal and electrical conductivity. It is currently widely used in graphite electrodes, graphite molds, graphite crucibles, 3D hot bending molds (mainly mobile phone glass hot bending molds), and other graphite products. In Europe, where manufacturing technology is leading, more than 90% of the electrode materials of mold companies are graphite.
How to choose the right graphite processing tool?
1. Tool material.
Tool material is an important factor that determines the cutting performance of the tool, and has a great impact on processing efficiency, processing quality, processing cost, and tool durability. The harder the tool material, the better its wear resistance, but the higher the hardness, the lower the impact toughness and the more brittle the material. Hardness and toughness are contradictory, which is a problem that tool materials should solve. For graphite tools, for ordinary TiAlN coatings, you can choose materials with relatively better toughness, that is, with a slightly higher cobalt content; for diamond-coated graphite tools, you can choose materials with a relatively high hardness, that is, with a slightly lower cobalt content; for polycrystalline diamond PCD tools, you can choose coarse-grained ones with better wear resistance.
2. Tool geometric angle.
Choosing an appropriate geometric angle for graphite-specific tools will help reduce the vibration of the tool. In turn, the graphite workpiece will not be easily chipped.
3. Coating of cutting tools.
Diamond-coated tools have the advantages of high hardness, good wear resistance, and low friction factor. At present, diamond coating is the best choice for graphite processing tools, and it can also better reflect the superior performance of graphite tools.
4. Passivation of the cutting edge of the tool.
The purpose of tool passivation is to solve the above-mentioned micro-notch defects in the sharpened tool edge, reduce or eliminate the sharpness, and achieve the purpose of being smooth, sharp, strong, and durable.
5. Machining conditions of cutting tools.
Choosing appropriate machining conditions has a considerable impact on tool life.
Based on the above points, the material, geometric angle, coating, edge strengthening, and machining conditions of the tool play different roles in the service life of the tool. Each one is indispensable and complements the other. A good graphite tool should have smooth graphite powder chip removal grooves, long service life, be able to perform deep engraving processing, and save processing costs.