Thermal shock resistance of advanced ceramics

Thermal shock resistance is the ability of a material to withstand rapid changes in temperature without cracking or failure. While advanced ceramics are known for their hardness and strength, they are susceptible to sudden temperature changes due to their inherent brittleness and low tolerance for thermal expansion. Therefore, thermal shock resistance is a key indicator when selecting ceramics for use in high-temperature, high-stress environments.

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Why thermal shock resistance is so important for ceramics

Ceramics typically operate in environments with extreme and unpredictable temperature variations:

Mechanical seals and bearings: Sudden contact with coolant after high speed rotation.
Plasma and laser nozzles: repeated exposure to hot gases and rapid cooling.
Semiconductor and LED equipment: Thermal cycling during manufacturing and operation.
Automotive and aerospace components: rapid heating/cooling by combustion or airflow.

Without proper thermal shock resistance, even high-strength ceramics can fail suddenly, leading to equipment damage, safety risks and increased maintenance costs.

factor

High thermal conductivity → lower temperature gradient
Low coefficient of thermal expansion → Reduced thermal stress
High fracture toughness → resistance to crack extension
High strength and good densification → increase critical thermal shock temperature difference ΔTc

CONCLUSION: Materials with lower thermal expansion and higher thermal conductivity generally exhibit better resistance to thermal shock.

Design Principles

Try to use ceramics with low coefficient of thermal expansion and high thermal conductivity
Reduction of stress concentrations within the ceramic (optimized structural design)
Avoid sharp corners, use rounded corners
Optimize material thickness and heat dissipation paths
Installation of redundant components or insulation in areas with frequent thermal shocks
Introduction of ceramic composite toughening technology where necessary

Thermal shock resistance data for key advanced ceramics

Selecting advanced ceramics for thermal shock conditions requires a balance of mechanical strength, thermal expansion and thermal conductivity. While no single material is perfect for all requirements, tailored choices can achieve optimal performance under thermal cycling stresses.

At Great Ceramic, we provide materials advice and precision machining for a wide range of thermal applications from aerospace to the semiconductor industry.

makings	heat conductivity(W/m-K)	thermal expansion(10-⁶/K)	Typical ΔT Tolerance (°C)	hallmark
Silicon Nitride (Si₃N₄)	20-30	2.8-3.3	500~700	High fracture toughness + medium-high thermal conductivity, preferred material for thermal shock resistance
Silicon Carbide (SiC)	120	4.0-4.5	350~500	High thermal conductivity + high strength, widely used in metallurgy, chemical thermal environment
Aluminum Nitride (AlN)	175	4.5-5.3	300~500	Highly thermally conductive ceramics, widely used in thermal management systems
Beryllium oxide (BeO)	230	7.5-9.0	~250	Ultra-high thermal conductivity, but toxic, limited use
Zirconia toughened alumina	~15	7.5-8.0	~325	Toughened aluminum oxide for mild thermal shock environments
Boron Nitride (BN)	60-80 (hexadecimal)	1.0-2.0	~200	Extremely low coefficient of expansion but low strength, suitable for insulating interfaces
Glass ceramics can be processed	1.5-3.5	3.0-3.5	~200	Good machinability, but low thermal conductivity and strength
Zirconium oxide (ZrO₂)	2.5-3	10.0-11.5	~300	High toughness but low thermal conductivity, easy to crack due to sudden temperature changes
Aluminum oxide (Al₂O₃, 99.5%)	25-35	7.5-8.5	200~300	Commonly used ceramics, but not suitable for frequent thermal shock environments

*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 chart below uses the R parameter as an indicator (the higher the value, the better the performance) and ranks common materials by their approximate values of thermal shock resistance. These values are derived from materials databases and industry benchmarks.

■ Red. Advanced Ceramics ■ Yellow. Metals ▪ Green. Plastics

*Data is for reference only.

Applications based on thermal shock resistance of ceramics

Electrothermal electronic heat dissipation substrates (AIN ceramics)

Material: Aluminum Nitride (AlN)
Application Background: Devices such as IGBTs and power MOSFETs undergo frequent hot and cold interchanges during operation.
Key performance requirements: high thermal conductivity, insulation and thermal shock resistance.
Benefits: Ceramic substrates are subjected to sharp thermal gradients during soldering or current transients, whereas AlN can withstand temperature differences of >400°C, preventing cracking or peeling.

Cavities for vacuum electronics (BeO ceramics)

Material: Beryllium oxide (BeO)
Application Scenario: High frequency vacuum tubes, microwave devices.
Thermal shock resistance: BeO has both high thermal conductivity and excellent thermal shock resistance, and can withstand the instantaneous temperature rise during high-power operation.

High-temperature fused glass sticks (Si₃N₄ ceramics0)

Material: Silicon Nitride (Si₃N₄)
Application background: Repeated submergence between high temperature molten glass and the cooling zone in the glass manufacturing process.
Advantages: Silicon nitride can withstand 1500 ℃ high temperature, can quickly from high temperature into cold water without blowing up, better than aluminum oxide or metal materials.

Hot press molds (ZTA ceramics)

Material used: ZTA20 (zirconia toughened alumina)
Industry background: Hot pressing, powder metallurgy industry.
Advantages: molds are prone to thermal cracks when repeatedly heated and cooled. zta improves the toughness and thermal shock resistance of molds and extends the service life of molds.

High-temperature and high-pressure sterilization equipment

Material: high purity aluminum oxide (Al₂O₃ 99.7%)
Application background: Medical ceramic parts need to withstand repeated cycles of high temperature and high pressure sterilization (autoclaving) at 121°C~135°C.
Benefits: High purity alumina can withstand the high temperature → cooling cycles of multiple sterilization processes, ensuring structural stability and biological inertness.

Hydrogen fuel cell stack insulator (SiC ceramic)

Material used: atmospheric pressure sintered silicon carbide (SSiC)
Application background: Operating temperature up to 800℃~1000℃, frequent hot start and cold start and stop.
Advantage: SiC has excellent thermal conductivity and thermal shock stability, preventing structural cracking due to thermal fatigue.

Ceramic pipe lining in solar molten salt systems

Material: Silicon Nitride or Silicon Carbide
Application background: Equipment for conveying high-temperature molten salts (>700°C).
Advantages: Large daily temperature fluctuations, Si₃N₄ or SSiC ceramic lining can avoid thermal fatigue cracking and maintain long-term airtightness and mechanical strength.