Graphite Heating Element and Heater for Vacuum Furnace Hot Zone
Product Overview
Our graphite heating elements are high-temperature resistive heaters used as the primary heat source in vacuum and controlled-atmosphere furnaces operating from 1000°C to 2400°C. Graphite heaters offer uniform radiant heating, fast thermal response, and excellent high-temperature strength compared to metal heating elements (Kanthal, Nichrome, MoSi2) that soften or oxidize above 1800°C. We manufacture graphite heater elements in strip, rod, plate, and cylindrical configurations, precision-cut to match existing vacuum furnace hot-zone layouts.
Graphite heating elements are consumable components in vacuum brazing, sintering, graphitization, and crystal growth furnaces. Over time, elements thin through evaporation and oxidation until resistance becomes too high for furnace operation. At Jincheng Graphite, we manufacture replacement graphite heaters that match original equipment dimensions, resistance values, and mounting configurations. Our engineering team can also design custom heater geometries for new furnace builds, upgrading from metal elements to graphite for higher temperature capability.
Key Features
- High temperature capability - operates up to 2400°C in vacuum or inert gas
- Uniform radiant heating - provides even temperature distribution across the work zone
- Fast thermal response - rapid heating and cooling cycles improve furnace throughput
- Multiple configurations - strip, rod, plate, and cylindrical heater designs
- Matched resistance - elements cut to target resistance for your transformer tap
- Precision mounting holes - drilled for existing element support systems
- Low thermal expansion - dimensional stability through thermal cycling
- Long service life - high-purity graphite minimizes evaporation rate
Technical Specifications
| Parameter | Value |
|---|---|
| Material | High-purity extruded / isostatic graphite |
| Bulk Density | 1.65 - 1.80 g/cm³ |
| Electrical Resistivity | 10 - 15 µΩ·m |
| Max Temperature | 2400°C (vacuum/inert) |
| Strip Thickness | 2 mm - 10 mm |
| Strip Width | 20 mm - 100 mm |
| Rod Diameter | 6 mm - 30 mm |
| Length Tolerance | ±1 mm |
| Hole Diameter | 6 mm - 12 mm (custom) |
| Hole Position Tolerance | ±0.5 mm |
| Surface Loading | 10 - 20 W/cm² (typical) |
| Lead Time | 10-20 business days |
Applications
- Vacuum brazing furnaces - graphite elements for high-temperature vacuum brazing
- Vacuum sintering furnaces - heaters for PM and carbide sintering
- Graphitization furnaces - high-temperature elements for carbon material graphitization
- Crystal growth furnaces - heaters for Czochralski and floating-zone growth
- CVD coating furnaces - elements for chemical vapor deposition chambers
- Laboratory high-temperature furnaces - custom elements for research furnaces
Why Choose Jincheng Graphite?
- Heater design expertise - understand resistance, power, and furnace geometry
- Replacement matching - match original element dimensions and resistance
- Custom heater design - design elements for new furnace builds
- Precision machining - holes and slots cut to exact mounting positions
- Material consistency - batch-to-batch resistivity consistency
- Cost savings - 50-70% lower than OEM vacuum furnace element replacements
- Fast delivery - standard strip elements ship within 10-15 days
- Technical support - we help optimize element layout and power distribution
FAQ
Q: How do I know what resistance my replacement heater needs?
A: Provide us with your furnace transformer specifications (secondary voltage range, current rating, and tap settings) and your target maximum temperature. Our engineering team will calculate the required heater resistance and design element geometry to match. If you have a worn element sample, we can measure its resistance and replicate it.
Q: Why do graphite elements thin out over time?
A: At high temperatures in vacuum, graphite sublimes directly from solid to gas, causing gradual material loss. The process accelerates above 2000°C. Element replacement is needed when resistance increases by 20-30% or when the element cross-section has thinned by half.
Q: Can I upgrade from metal elements to graphite?
A: Yes. Many furnace owners upgrade from Kanthal or SiC elements to graphite to reach higher temperatures and improve uniformity. However, graphite requires a vacuum or inert gas atmosphere (it oxidizes in air above 450°C). Contact us with your furnace details and we will evaluate the upgrade.
Q: How should I store spare graphite heaters?
A: Store spare elements in a dry, clean environment, preferably in sealed plastic with desiccant. Graphite is porous and absorbs moisture, which can cause outgassing during initial furnace heat-up. Bake out new elements at 1000°C under vacuum before production use.
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