Materials
Precision Ceramics
Advanced technical ceramics — alumina, silicon nitride, boron nitride, and silicon carbide — engineered for demanding semiconductor, high-temperature, and wear applications.
Advanced Technical Ceramics at Tuguan
Precision ceramics fill the performance gap between quartz glass (chemically pure, low thermal expansion) and metals (thermally conductive, tough). Depending on the grade selected, technical ceramics offer:
- Extreme hardness and wear resistance (Al₂O₃, SiC)
- Thermal shock resistance (Si₃N₄)
- Electrical insulation at high temperatures (Al₂O₃, BN)
- Thermal conductivity (BN, SiC)
- Chemical inertness in plasma and corrosive environments
Alumina — Al₂O₃
Why Alumina?
Alumina is the workhorse of technical ceramics. At ≥ 99.5% purity, it combines high hardness, electrical insulation up to 1600°C, and excellent chemical resistance at a cost-effective price point.
| Property | 96% Al₂O₃ | 99.5% Al₂O₃ | 99.9% Al₂O₃ |
|---|---|---|---|
| Density | 3.72 g/cm³ | 3.89 g/cm³ | 3.96 g/cm³ |
| Hardness | 1100 HV | 1400 HV | 1600 HV |
| Flexural Strength | 300 MPa | 380 MPa | 500 MPa |
| Max Use Temp (air) | 1500°C | 1600°C | 1700°C |
| Thermal Conductivity | 17 W/(m·K) | 28 W/(m·K) | 35 W/(m·K) |
| Dielectric Strength | 8 kV/mm | 10 kV/mm | 12 kV/mm |
| Volume Resistivity (RT) | > 10¹⁴ Ω·cm | > 10¹⁴ Ω·cm | > 10¹⁴ Ω·cm |
Typical semiconductor applications:
- Wafer carrier and boat (for processes where quartz would contaminate)
- Isolation rings and spacers
- High-temperature electrical insulators
- Plasma-resistant chamber liners
Silicon Nitride — Si₃N₄
Why Silicon Nitride?
Si₃N₄ combines high strength, exceptional thermal shock resistance, and moderate thermal conductivity. It is the premier ceramic for applications involving rapid thermal cycling.
| Property | Value |
|---|---|
| Density | 3.20–3.25 g/cm³ |
| Hardness | 1400–1700 HV |
| Flexural Strength | 700–1000 MPa |
| Fracture Toughness (KIC) | 5–7 MPa·m½ |
| Max Use Temp (neutral atmosphere) | 1400°C |
| Thermal Conductivity | 20–80 W/(m·K) |
| Thermal Expansion Coefficient | 3.0–3.5 × 10⁻⁶/°C |
| Thermal Shock Resistance (ΔT) | > 500°C |
Key advantage over alumina: Si₃N₄ has 2–3× higher fracture toughness, making it far less prone to cracking under thermal shock — critical for components subjected to rapid heating/cooling cycles.
Typical applications:
- Wafer handling pins and end-effectors
- High-cycle thermal processing components
- Bearing elements in high-temperature equipment
- Shot-blast nozzles and wear liners
Boron Nitride — BN (Hexagonal)
Why Boron Nitride?
Hexagonal BN (h-BN) is structurally analogous to graphite — layered, lubricating, easily machinable — but with excellent electrical insulation and high thermal conductivity.
| Property | Value |
|---|---|
| Density | 1.9–2.1 g/cm³ |
| Hardness | 50–60 HV (very soft — machinable with conventional tools) |
| Max Use Temp (inert atm.) | 2000°C |
| Max Use Temp (oxidizing) | 850°C |
| Thermal Conductivity | 25–60 W/(m·K) (perpendicular to pressing direction) |
| Thermal Expansion Coefficient | 0.5–6.5 × 10⁻⁶/°C (highly anisotropic) |
| Dielectric Strength | 35–65 kV/mm |
| Chemical Resistance | Excellent vs. most metals and slags |
Key advantages:
- Excellent machinability — can be machined to tight tolerances with standard carbide tooling
- Non-wetting — molten metals and glasses do not adhere to BN
- High electrical insulation + high thermal conductivity (unusual combination)
Typical applications:
- High-temperature crucibles and evaporation boats
- Heater support tubes and insulators
- Diffusion barriers in CVD equipment
- Thermocouple protection tubes
Silicon Carbide — SiC
Why Silicon Carbide?
SiC is the hardest of the four ceramic grades we offer, with outstanding thermal conductivity and thermal shock resistance at extreme temperatures.
| Property | Reaction-Bonded SiC | Sintered SiC |
|---|---|---|
| Density | 3.05–3.10 g/cm³ | 3.10–3.15 g/cm³ |
| Hardness | 2200–2600 HV | 2500–2700 HV |
| Flexural Strength | 350–450 MPa | 400–550 MPa |
| Max Use Temp (inert) | 1380°C | 1650°C |
| Thermal Conductivity | 110–150 W/(m·K) | 80–120 W/(m·K) |
| Thermal Expansion | 4.0–4.5 × 10⁻⁶/°C | 4.0–4.5 × 10⁻⁶/°C |
Typical applications:
- Susceptors and carriers for RTP (rapid thermal processing)
- Etching ring alternatives where extreme plasma resistance is needed
- High-temperature nozzles and wear components
- Heat exchangers and burner nozzles
Machining Technical Ceramics
All four ceramic grades require diamond-tooled machining. Our capabilities:
| Process | Alumina | Si₃N₄ | BN | SiC |
|---|---|---|---|---|
| Tolerance (tight features) | ±0.02 mm | ±0.02 mm | ±0.05 mm | ±0.03 mm |
| Surface Roughness | Ra 0.4–1.6 μm | Ra 0.4–0.8 μm | Ra 1.6–3.2 μm | Ra 0.4–1.6 μm |
| Drilling (min hole Ø) | 0.8 mm | 1.0 mm | 0.5 mm | 1.0 mm |
| Max Part Size | 400 mm | 300 mm | 300 mm | 300 mm |
| Grinding (OD/flat) | ✓ | ✓ | Limited | ✓ |
| Sintering / HIP | Sourced | Sourced | Sourced | Sourced |
Note: BN is unique in that it can be machined with conventional carbide or HSS tooling, enabling rapid prototyping and complex geometries without expensive diamond tooling lead times.
Material Selection Guide
| Requirement | Recommended Grade |
|---|---|
| Highest purity electrical insulation at 1600°C | Al₂O₃ 99.9% |
| Best thermal shock resistance | Si₃N₄ |
| Machinable + insulating + thermally conductive | h-BN |
| Hardest + best thermal conductivity at high temp | SiC |
| Cost-effective general ceramic | Al₂O₃ 96% |
Not sure which grade fits your application? Contact our engineers with your operating conditions and we’ll recommend the optimal solution.