Graphite molds hold irreplaceable status in metal casting, glass forming, and semiconductor packaging due to their exceptional high-temperature stability, electrical conductivity, self-lubrication, and chemical inertness. This article systematically elaborates the complete process of customized graphite mold production, covering core procedures including material selection, cutting forming, rough/finish machining, precision control, and logistics delivery, providing technical reference for industrial users.
I. Material Selection: Performance Matching Determines Mold Lifespan
The quality of graphite materials directly affects machining performance and service life. Current mainstream materials include:
- Isostatic graphite (Density ≥1.82g/cm³):
Features isotropic properties and high purity (ash content <5ppm), suitable for precision applications like semiconductor wafer fixtures. - Molded graphite (Compressive strength ≥80MPa):
Cost-effective solution for medium-precision applications such as glass hot bending molds. - Extruded graphite (Particle size ≤10μm):
Ideal for precision die-casting molds requiring surface finish.
Material selection requires comprehensive consideration of:
- Operating temperature (up to 3000℃)
- Corrosion resistance (e.g., molten metal contact)
- Electrical conductivity requirements
For instance, photovoltaic monocrystalline furnace components require high-purity graphite (ash <20ppm), while standard casting molds can utilize economical medium-coarse grain materials.
II. Cutting Forming: Precision Blanking Establishes Machining Foundation
Primary processing employs two cutting technologies:
- CNC wire cutting:
- 0.2mm molybdenum wire
- ±0.05mm precision
- Suitable for complex contours
- Laser cutting:
- 10m/min cutting speed
- Heat-affected zone <0.1mm
- Optimal for mass production
Key considerations:
- Maintain 0.3-0.5mm machining allowance
- Align with graphite layered structure orientation
- Implement ultrasonic cleaning post-cutting to prevent edge chipping
III. CNC Rough Machining: Efficient Forming with Cost Control
3/4-axis CNC milling removes 80% material:
- Tools: Diamond-coated carbide (Ø6-12mm)
- Parameters: 8,000-12,000rpm, 800-1200mm/min feed rate
- Dry cutting with vacuum dust collection
Process control:
- Layer cutting (≤2mm depth per pass)
- Path optimization
- Maintain ±0.1mm tolerance
- Conduct preliminary dimensional inspection
IV. Precision Machining: Achieving Micron-level Accuracy
- Surface finishing:
- Ball-end mills (R1-R3)
- Surface roughness Ra ≤0.8μm
- Micro-hole processing:
- EDM for holes <Ø0.5mm
- ±0.005mm precision
- Edge treatment:
- C0.2 chamfering
- 800# diamond wheel polishing
Tool management:
- Real-time wear monitoring
- Replace inserts every 50 cycles
V. Quality Control System
Three-tier inspection protocol:
- In-process inspection:
- Dimensional sampling after each operation
- Final inspection:
- CMM full-dimension measurement
- Profile comparison with optical projector
- Helium mass spectrometer leak test (for vacuum molds)
VI. Packaging & Logistics Solutions
Multi-level protective packaging:
- Primary packaging:
- Anti-static PE foam wrapping
- Secondary protection:
- Custom wooden crate (humidity <10%)
- Silica gel desiccant
- Transportation:
- Door-to-door delivery for precision components
- Vibration levels controlled below 0.5G
- Real-time temperature/humidity monitoring
- Vacuum moisture-proof packaging for international shipping (humidity <60%)
Conclusion
Modern graphite mold manufacturing has evolved into a comprehensive digital production chain. Through integration of materials science, precision machining, and quality engineering, the industry is advancing toward ±0.5μm precision machining and intelligent adaptive manufacturing. Mastering these core process technologies proves essential to meet stringent requirements from emerging fields like new energy vehicle battery module molds.
