CVD Diamond Coated Cutters for Graphite & EDM Graphite Electrode Machining
1. Critical Difficulties in Graphite Machining
High-purity fine-grain graphite is the mainstream material for EDM electrodes. Graphite cutting generates abrasive fine dust that continuously abrades cutting edges:
- Uncoated carbide tools wear and chip severely within 30 minutes of graphite milling, leading to defective electrode corners and scrapped workpieces;
- Tool wear causes dimensional drift during thin-wall, micro rib and deep cavity graphite machining, poor batch consistency;
- Graphite dust clogs chip flutes, generates localized overheating and accelerates tool failure, frequent tool changes reduce CNC utilization rate heavily.
2. Unique Advantages of CVD Diamond Coating on Graphite
- Extreme abrasion resistance against graphite dust: Diamond hardness withstands continuous scratching from graphite particles, tool life 10–30 times longer than standard carbide;
- High thermal conductivity eliminates thermal burn: Fast heat dissipation prevents blackening and carbonization on electrode edges, flawless surface finish;
- Dense smooth diamond film avoids dust adhesion on flutes, smooth chip removal for high-speed dry milling;
- Compatible with miniature & long-reach tools: CVD uniformly coats micro, extended, ball nose cutters, stable machining for complex curved and micro rib electrodes.
3. Tool Selection Guide
- Graphite roughing: Multi-flute corn cob diamond coated end mills with large chip pockets for high stock removal;
- Micro electrode finishing: 2-flute nano diamond micro end mills & ball nose tools to keep sharp corners intact;
- Deep long graphite cavities: Gradient stress CVD long flute cutters to prevent coating delamination.
4. Recommended Machining Parameters
Cutting speed Vc: 600~1200 m/min; Feed per tooth fz: 0.08~0.25 mm/z; Full dry cutting with industrial dust extractor, climb milling preferred.
5. Application Fields
Plastic mold EDM graphite electrodes, die-cast mold electrodes, 3C precision mold inserts, semiconductor packaging molds, micro electrical discharge machining electrodes.
6. Operation Notes
Powerful dust extraction system is mandatory during graphite machining; Coolant liquid contact with graphite shall be avoided to prevent dust agglomeration.
