Performance Parameters of Mullite Ceramics

Mullite ceramic (3Al₂O₃·2SiO₂) is a high-performance engineering ceramic known for its excellent thermal stability, low thermal expansion, and outstanding thermal shock resistance. This material is widely used in the fields of high-temperature industry, electronic packaging, and refractory materials.

About Mullite Ceramic

Mullite ceramics are composed of alumina (Al₂O3) and silica (SiO₂), with a unique needle like crystal structure that endows them with high mechanical strength, low thermal conductivity, and excellent creep resistance.

According to the composition ratio, mullite ceramics can be divided into:

Standard mullite (72% Al₂O₃): used in high-temperature environments such as refractory bricks and kiln furniture.

High alumina mullite (≥ 75%Al₂O₃): suitable for industrial furnace linings and electronic substrates at higher temperatures.

Characteristics of Mullite Ceramics

physical property

Color: White or off white (the higher the purity, the whiter)

Density: 2.7-3.2 g/cm ³ (lower than alumina, lighter weight)

Thermal expansion coefficient (25-1000°C): 4.5-5.5 × 10⁻⁶/K (much lower than alumina, excellent thermal shock resistance)

Mechanical properties

Bending strength: 120-200 MPa

Hardness: 6-7 Mohs

Elastic modulus: 150-220 GPa

Thermal Properties 

Maximum operating temperature: 1650°C (long-term stable)

Thermal conductivity: 3-5 W/(m·K) (low thermal conductivity, suitable for insulation applications)

Electrical Property

Volume resistivity (20°C):>10¹⁴Ω· cm (excellent insulator)

Dielectric constant (1MHz): 6-7

Advantages of Mullite Ceramics

✔  Super strong thermal shock resistance - able to withstand rapid cooling and heating (Δ T>800°C)

✔  High temperature stability - no phase transition, no deformation at 1600 ° C

✔  Low thermal expansion - matching metal/alloy to reduce thermal stress cracking

✔  Chemical corrosion resistance - resistance to molten metal/slag erosion

✔  Lightweight -15-20% lighter than alumina

Typical Applications of Mullite Ceramics

Refractory materials: kiln lining bricks, sintering trays, thermocouple protection tubes

Electronics industry: IC packaging substrates, high-frequency insulation components

Energy and environmental protection: thermal barrier coatings for gas turbines, catalytic converter carriers

Glass Manufacturing: Glass Furnace Flow Hole Lining Plate

Aerospace: Rocket nozzle insulation layer

conclusion

Mullite ceramics are the preferred material for high-temperature, thermal insulation, and thermal shock resistant environments, especially suitable for fields that require synergistic optimization of lightweight and thermal stability. Mullite provides an irreplaceable solution for extreme thermal cycling conditions that alumina ceramics cannot meet, such as glass kilns and aerospace components.

If you need to customize mullite ceramic components (such as shaped refractory parts, insulation sleeves), please feel free to provide technical parameter acquisition solutions!