Material Composition and Characteristics
Carbon graphite is a synthetic composite material formed by combining an amorphous carbon matrix with flake graphite, exhibiting a steel-gray to deep black gradient. Its core properties derive from a unique dual-phase structure:
Property Category | Performance Specifications | Mechanism |
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Thermal Stability | Oxidative (200-600°C) Inert (≤3000°C) Cryogenic (-270°C) | Stability of sp²-hybridized carbon network |
Corrosion Resistance | Resists petroleum derivatives, SO₂ | Covalent-bonded hexagonal lattice |
Self-Lubrication | Dry friction coefficient: 0.08-0.15 | Weak van der Waals forces between graphene layers |
Controlled Porosity | Porosity: 15-30% | Pyrolytic volatilization creating porous network |
Advanced Manufacturing Process
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Raw Material Compounding
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Amorphous carbon (Vickers hardness: 150-300 HV)
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Natural flake graphite (particle size: 20-80μm)
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Coal tar pitch binder (softening point: 90-110°C)
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Forming & Carbonization
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Isostatic pressing (100-200 MPa)
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Carbonization at 800-1200°C (N₂ atmosphere)
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Mass reduction: 15-25% (volatile removal)
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Graphitization Enhancement
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Acheson furnace treatment (2500-3000°C)
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Functional impregnation:
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Metal impregnation (enhances thermal conductivity)
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Resin filling (improves corrosion resistance)
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Solid lubricants (optimizes tribological properties)
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Comparative Performance Analysis
Parameter | Carbon Graphite | Pure Graphite |
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Density (g/cm³) | 1.7-1.9 | 2.1-2.3 |
Compressive Strength (MPa) | 80-150 | 20-50 |
CTE (×10⁻⁶/K) | 2.5-5.5 | 0.5-4.5 |
Engineering Advantages
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Extreme Temperature Adaptability: Maintains dimensional stability (CTE<5.5×10⁻⁶/K) from -270°C to 3000°C
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Self-Sustaining Lubrication: Dynamic transfer film reduces wear rate to 10⁻⁶ mm³/N·m magnitude
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Chemical Inertness: Stable in pH 0-14 environments (excluding strong oxidizers)
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Precision Machinability: Achievable tolerance: ±0.005 mm
Industrial Applications
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Fluid Control Systems: Ball valve seats (cryogenic service)
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Rotating Machinery Components:
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Centrifugal pump impellers (ANSI/API 610)
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Compressor bearings (ISO 10438)
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Specialized Sealing Elements:
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Mechanical seal rings (API 682 standard)
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Nuclear-grade graphite seals
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Wear-Resistant Components:
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Wafer handling carriers
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High-temperature guide plates
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Graphite-structure
Material Enhancement Pathways
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Nano-Reinforcement: 5% graphene addition increases mechanical strength by 40%
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Composite Impregnation: Copper + MoS₂ dual-phase impregnation elevates PV limit to 5.0 MPa·m/s
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Surface Functionalization: CVD silicon carbide coating enables 800°C oxidation resistance
Industrial data indicates carbon graphite components extend service life by 300% in abrasive media pumps compared to conventional materials.
Material Selection Guidelines
Operating Condition | Recommended Grade |
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High load (>50 MPa) | Bronze-impregnated CB series |
Highly corrosive environments | PTFE-impregnated CGW type |
Food/Pharmaceutical grade | FDA-compliant resin impregnation |
This composite material integrates graphite’s self-lubrication with amorphous carbon’s mechanical strength, serving as an irreplaceable engineering solution in aerospace, energy equipment, and precision manufacturing sectors.