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Silicon Carbide (SiC) Advanced Ceramics

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Product Description

Silicon Carbide (SiC) Advanced Ceramics – Product & Technical Capabilities

1. Manufacturing Process

Our high-performance silicon carbide (SiC) ceramics are produced via pressureless solid-phase sintering, utilizing a fully integrated in-house production line:

SiC powder granulation → Green body forming → High-temperature sintering → Precision machining
Each batch can be supplied with a certified material property test report (including density, flexural strength, coefficient of thermal expansion, thermal conductivity, etc.)

2. Customizable Dimensions

Maximum producible size: 700 (L) × 415 (W) × 300 (H) mm
Complex geometries and post-sintering precision machining are supported

3. Key Material Properties

Property	Unit	Typical Value
Density	g/cm³	≥ 3.10
Flexural Strength (3-point bending, RT)	MPa	≥ 400
Elastic Modulus	GPa	380 – 420
Weibull Modulus	—	≥ 12
Fracture Toughness (K₁C)	MPa·m¹/²	3.0 – 4.5
Vickers Hardness (load 9.8 N)	GPa	22 – 28
Coefficient of Thermal Expansion (25–500°C)	×10⁻⁶/K	2.5 – 3.0
Thermal Conductivity (RT)	W/(m·K)	140 – 180
Specific Heat Capacity (RT)	J/(kg·K)	680 – 750
Maximum Service Temperature (inert atmosphere)	°C	≥ 1600
Electrical Resistivity	Ω·cm	10² – 10⁵
Poisson’s Ratio	—	0.16 – 0.19
Surface Roughness (post-polishing, after Si modification)	nm (Ra)	≤ 0.5
Porosity	%	< 2

4. Performance Advantages

High specific stiffness (E/ρ ≈ 125 – 135 × 10⁶ m²/s²) – ideal for lightweight, large-aperture structures
Low coefficient of thermal expansion + high thermal conductivity – superior thermal stability and resistance to thermal distortion
Significant weight reduction capability – enabling replacement of metallic or fused silica mirror substrates
Excellent mechanical strength and hardness – ensures dimensional stability during thin-wall fabrication and assembly

Silicon carbide has been widely recognized as the preferred substrate material for large-scale lightweight mirrors. Chinese researchers have successfully developed a Φ4-meter SiC aspherical mirror, demonstrating the material’s scalability and feasibility for demanding applications.

5. Applications

Semiconductor lithography and inspection equipment (mirrors, reference components)
High-power laser systems (lightweight mirrors, scanning galvanometer mirrors)
Astronomical telescopes (primary and secondary mirrors)
High-precision optical benches and thermally stable structural components

6. Surface Modification & Super-Polishing

Surface modification via silicon (Si) infiltration / coating is available
After modification, the surface can be super-polished to achieve:
- Surface roughness: Ra < 0.5 nm (RMS)
Meets stringent requirements for optical reflectivity and surface figure accuracy