Silicon Carbide(SiC/SiSiC)

Silicon carbide (SiC) is one of the hardest ceramic materials, just after diamond. It stands out for its excellent wear resistance and heat dissipation, making it ideal for use in a wide range of industries, from electronics and automotive to aerospace and industrial machinery. SiC remains stable across a broad temperature range and resists thermal deformation, which adds to its reliability in tough conditions. It also boasts low thermal expansion, great thermal conductivity, and impressive resistance to acids and alkalis. The two main types, SSiC (sintered silicon carbide) and SiSiC (silicon infiltrated silicon carbide), are especially suited for producing large, complex components, offering outstanding performance where durability and precision are essential.

(SiC/SiSiC) Advantages

Good gliding properties
Non-toxic and environmentally safe
Hardness second only to diamond
Excellent high-temperature resistance
High Young’s modulus (380 to 430 GPa)
Excellent thermal shock resistance (ΔT = 1,100 K)
Corrosion and wear resistant even at high temperatures
Maintains high strength under both high and low temperature conditions

(SiC/SiSiC) Applications

High-temperature and high-voltage power semiconductor devices
Wear-resistant mechanical seals
Heat exchangers
High-temperature sensors
Optical reflectors
SiC ceramic bearings
Energy technology components
Pipeline system components
Semiconductor vacuum chuck, ceramic chuck
Refractory linings for high-temperature environments

Material Properties

Property	Unit	Silicon Carbide
Density	g/cm³	3.15
Vickers Hardness	Hv0.5	2650
Bending Strength	MPa	450
Compressive Strength	MPa	2650
Elastic Modulus	GPa	430
Toughness	MPa·m¹/²	4
Poisson’s Ratio	–	0.14
Young’s Modulus	GPa	430
Purity of Silicon Carbide	%	99

Thermal Properties

Property	Unit	Silicon Carbide
Thermal Conductivity @ 25°C	W/mK	110
Melting Point	°C	2800
Specific Heat Capacity	J/gK	0.8
Linear Expansion Coefficient	10⁻⁶/K	4

Electrical Properties

Property	Unit	Silicon Carbide
Dielectric Constant (1 MHz)	–	10
Breakdown Voltage	V/cm	1×10⁶
Dielectric Loss (1 MHz)	–	0.001
Resistivity	Ω·cm	10⁷–10⁹

Note: This value is for reference only and may vary slightly depending on the batch conditions.

Silicon Carbide Machining

Silicon carbide (SiC) machining is a challenging yet essential process for producing high-performance components used in extreme environments. Known for its exceptional hardness, high thermal conductivity, and wear resistance, SiC is commonly used in industries such as aerospace, automotive, electronics, and energy. Machining SiC requires specialized tools and techniques, as the material’s hardness and brittleness make it difficult to cut and shape using traditional methods. Precision grinding, diamond tooling, and laser machining are often employed to achieve the desired dimensions and surface finishes. Advanced techniques like waterjet cutting and ultrasonic machining can also be used for complex geometries. Proper machining of silicon carbide ensures the production of durable, high-quality parts that maintain stability in high-temperature, high-pressure, and chemically aggressive environments.

Prototype Machining Video

This is a ceramic prototype machining video from Jundro

Custom Silicon Carbide Parts

We have supplied various SiC parts for the semiconductor and machinery industries, including wear-resistant mechanical seals, ceramic guide rails, ceramic mirrors, SiC etching rings, SiC vacuum chucks, wafer chucks, and pin-type, ring-type, and groove-type chucks.

Frequently Asked Questions

What is the friction coefficient of Silicon Carbide (SiC) ceramics?

The friction coefficient of SiC typically ranges from 0.15–0.25 in dry conditions and 0.05–0.10 with lubrication, depending on surface finish, load and environment. Polished SiC shows the lowest friction and excellent wear resistance, making it ideal for mechanical seals and sliding components.

Can Silicon Carbide be polished to a mirror finish?

Yes. SiC can be polished to a true mirror finish, typically achieving Ra ≤ 0.001 using fine diamond grinding and chemical–mechanical polishing.

How does the bandgap of SiC compare to GaN, and what advantages does it offer?

SiC has a wide bandgap of ~3.2 eV, slightly lower than GaN (~3.4 eV), but it offers unique advantages:

Higher thermal conductivity (~120–200 W/m·K vs ~130 for GaN)
Higher breakdown voltage
Excellent thermal stability for high-power devices
Better substrate availability and cost compared to GaN-on-SiC
This makes SiC ideal for high-power, high-temperature, and high-voltage applications such as EV inverters, power modules, and industrial power systems.

Why is SiC the mainstream material for mechanical seal rings?

SiC is widely used for mechanical seals because it offers:

Very high hardness and superior wear resistance
Low friction coefficient
Excellent chemical and corrosion resistance
High thermal conductivity for heat dissipation
Dimensional stability under temperature and pressure
These properties ensure long service life, low leakage, and reliable performance in pumps, compressors, and chemical processing equipment.

How should I choose between sintered SiC, SSiC, RBSiC, and CVD SiC?

SSiC (Sintered SiC): Highest strength, purity, hardness, and corrosion resistance. Best for mechanical seals, semiconductor parts, and high-wear components.
RBSiC (Reaction-Bonded SiC): Lower cost, easier to form complex shapes, but slightly lower strength and some residual Si. Good for structural parts and large components.
CVD SiC: Ultra-pure, extremely dense, mirror-polish capable, ideal for semiconductor, optical, and vacuum applications. Highest performance and cost.
How to choose:
- Wear & sealing: SSiC
- Complex shapes & lower cost: RBSiC
- Optical/semiconductor: CVD SiC
- High-temperature structural: SSiC

Does Silicon Carbide support small-batch customization? What is the minimum order quantity (MOQ)

Yes. SiC components can be produced in small batches using diamond grinding, ultrasonic machining, or laser processing.

MOQ: Typically 1 pieces for prototypes, depending on geometry.
Lead Time: Usually 2–4 weeks for small batches; complex parts may require longer.
Professional machining shops like Jundro Ceramic provide low-volume precision SiC manufacturing with full QC reports and material traceability.