Thermal conductivity of advanced ceramics

Thermal conductivity (k, in W/m-K) measures a material's ability to conduct heat - a key property for electronics, aerospace, energy and industrial applications. In this article, we look at how advanced ceramics compare to metals and plastics, their importance, and their application areas.

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Why Ceramic Thermal Conductivity Matters

Ceramics are widely used for thermal management due to their uniquely high thermal conductivity and excellent electrical insulation. Unlike metals, which conduct both heat and electricity, advanced ceramics such as aluminum nitride (AlN), beryllium oxide (BeO), and silicon carbide (SiC) are able to transfer heat efficiently while blocking the flow of electrical current. This makes them ideal for electronic components, power devices, and high-temperature applications where electrical isolation and reliable heat dissipation are critical.

In addition, ceramics offer the following advantages:

High thermal stability at high temperatures
Corrosion resistance in harsh environments
Mechanical strength and durability under thermal cycling

These properties enable ceramics to serve as effective heat sinks, substrates and insulating radiators for industries such as electronics, aerospace, automotive and energy.

How do you determine where to apply the material?

Advanced ceramics with high thermal conductivity are suitable for core components of thermal management, such as electronic packaging, aerospace thermal control, and semiconductor heat sinks.
Medium thermal conductivity combined with high strength materials for dynamic high-temperature components such as highly loaded mechanical bearings and nozzles.
Low thermal conductivity materials are used for insulation and temperature control areas such as thermal barrier coatings and insulating spacers.

Thermal conductivity data for major advanced ceramics

Ceramic materials	kJ (w/m-Kelvin)	hallmark
Beryllium oxide (BeO)	230-330	Very high thermal conductivity, electrically insulating, toxic in powder form
Aluminum Nitride (AlN)	170-210	High thermal conductivity, electrical insulation, low dielectric loss
Silicon Carbide (SiC)	120-200	Extremely hard, excellent corrosion and wear resistance, high thermal conductivity
Boron nitride (h-BN)	~60	Lubricating, thermally stable, electrically insulating
Aluminum oxide (Al₂O₃)	25-35	High hardness, good abrasion resistance, excellent electrical insulation properties
Silicon Nitride (Si₃N₄)	20-30	High fracture toughness, thermal shock resistance, low density
Zirconium oxide (ZrO₂)	2-3	High toughness, low thermal conductivity, phase change toughening
Machinable Glass Ceramics (MGC)	~2	Easy processing, good dielectric strength, low thermal conductivity

*Data is for reference only.

Need help choosing the right ceramic?

Choosing the right high-strength ceramic material is critical to ensuring long-term reliability and optimal performance. Whether you need zirconia, silicon nitride, or alumina-based ceramics, our materials provide industry-leading strength, durability, and precision.

Our technical team is here to help - contact us today for expert customized advice on your specific needs.

Comparison: Ceramics vs. metals and plastics

The bar chart below shows the thermal conductivity of a variety of engineering materials - ranging from super-hard ceramics to common industrial plastics, in descending order.

Ceramic

Metal

Plastic

*Data is for reference only.

Applications based on ceramic thermal conductivity

Machinery and equipment

Applied Ceramics:
- Aluminum Nitride (AlN)
- Beryllium oxide (BeO)
- Silicon Nitride (Si₃N₄)
Applications:
- Insulating spacer for high thermal load bearing: Si₃N₄ ceramics have good thermal conductivity (about 20-30 W/m-K), high temperature resistance, impact resistance, and are used in high-speed spindles to effectively conduct heat and avoid overheating.
- Motor Heat Sink End Caps: AlN has a high thermal conductivity (approx. 170-220 W/m-K) and is commonly used in high-efficiency motor housings as an alternative to conventional metals to reduce weight and thermal stress.
- Heat exchange base for high power equipment: for cooling of power modules for CNC machine tools.

electronics industry

Applied Ceramics:
- Aluminum Nitride (AlN)
- Beryllium oxide (BeO)
- Aluminum oxide (Al₂O₃)
Applications:
- High frequency communication module heat dissipation substrate (AlN/BeO): high thermal conductivity (BeO>250 W/m-K), to ensure that the temperature of the microwave chip is controlled within a safe range, commonly used in 5G, radar modules.
- LED encapsulation heat dissipation substrate: AlN ceramics with high thermal conductivity and good insulation, is the mainstream material for high-power LED encapsulation.
- IGBT/Power Semiconductor Package Substrate: AlN substrate effectively suppresses localized overheating of the chip and improves its life.

New Energy Vehicle Sector

Applied Ceramics:
- Aluminum Nitride (AlN)
- Silicon Nitride (Si₃N₄)
- Aluminum oxide ceramics
Applications:
- Power Battery Thermal Management Ceramic Gaskets: AlN ceramics are used for battery module gaskets to conduct heat quickly and prevent thermal runaway.
- Power Module Substrates for Electronic Control Systems: Thermal substrates for SiC MOSFET modules to improve system cooling efficiency.
- Ceramic bearings for electric drive systems: Si₃N₄ has good thermal conductivity and electrical insulation properties, widely used in motor bearings to reduce energy consumption and temperature rise.

Aerospace

Applied Ceramics:
- Silicon Nitride (Si₃N₄)
- Aluminum Nitride (AlN)
- Beryllium oxide (BeO)
Applications:
- Thermal insulation/conductivity ceramic components for rocket propulsion systems: e.g., nozzle bushings, high-speed gas tubes, etc. Si₃N₄ combines heat resistance, thermal conductivity, and impact resistance.
- Satellite electronic component heat dissipation base: adopting BeO or AlN for efficient heat dissipation to ensure stable working temperature of aerospace electronic module.
- Thermal control of electronic equipment for high-speed aircraft: using AlN ceramics to dissipate heat from power components in flight control systems to improve system reliability.

Metallurgy/Smelting

Applied Ceramics:
- Silicon Nitride (Si₃N₄)
- Silicon Carbide (SiC)
- Aluminum oxide ceramics
Applications:
- Protective sleeve for steel fusion temperature probes (Si₃N₄, SiC): good thermal conductivity and chemical resistance, fast transmission of temperature signals and extended service life.
- Aluminum melting heat crucible/nozzle: The use of high thermal conductivity ceramics (e.g. SiC) allows for uniform heating and avoids localized overheating.
- Thermocouple protection sleeve: high thermal conductivity ceramic shell, rapid response to temperature changes, to ensure the accuracy of smelting temperature control.