Mullite_Mullite Ceramic Material Properties

Ceramic material

News

Mullite Ceramic

Location：Home > Ceramic material > Mullite Ceramic >

Mullite Ceramic - Introduction & Material Parameters
Mullite ceramic is a high-performance ceramic material with mullite as the main crystal phase. Mullite is a naturally occurring aluminum silicate mineral with a chemical formula of 3Al₂O₃·2SiO₂ (Al₆Si₂O₁₃), but synthetic mullite can optimize performance by adjusting the ratio of Al₂O₃ to SiO₂ (such as 2:1 or higher). It was first named in 1924 and has become a core material in the field of refractory materials and advanced ceramics due to its excellent stability at high temperatures. Composition The main components of Mullite are aluminum oxide (Al₂O₃) and silicon dioxide (SiO₂), with a typical molar ratio of 3:2, but artificial synthesis can be extended to 2:1 or even higher Al₂O₃ content. Main crystal phase: Mullite (3Al₂O₃·2SiO₂), alumina (Al₂O₃) content is between 71.8% and 77.3%, and silicon dioxide (SiO₂) content is between 22.7% and 28.2%. Impurities and additives: · Natural raw materials may contain impurities such as TiO₂, Fe₂O₃, CaO, MgO, etc. · Grain refinement and performance regulation can be achieved by adding oxides such as MgO and Y₂O₃ during artificial synthesis. Microstructure: The crystal is needle-shaped or columnar, and the grain size can be controlled by sintering temperature (1600-1800℃) and insulation time. The porosity is less than 1% and the density is high.

Performance characteristics

· High temperature stability: melting point is about 1850°C, and long-term use temperature reaches 1600°C.

· Low thermal expansion coefficient (~4.5×10⁻⁶/°C), thermal shock resistance is better than alumina ceramics.

· Mechanical properties: high hardness (Mohs hardness 6-7), good high temperature strength retention, but relatively brittle at room temperature.

· Chemical inertness: resistant to acid, alkali and molten metal corrosion.

· Insulation: low dielectric loss at high frequency, suitable for electronic devices.

· Lightweight: density 3.1-3.2 g/cm³, lower than most engineering ceramics.

Main Application Areas

· Refractory materials: steel furnace lining, glass kiln lining, ceramic kiln furniture.

· Electronics industry: integrated circuit substrates, high-frequency insulation components.

· Aerospace: thermal barrier coatings for turbine blades, rocket nozzle insulation.

· Environmental protection: high-temperature flue gas filters, catalyst carriers (such as diesel particulate filters).

· Chemical and energy: corrosion-resistant reactor linings, solid oxide fuel cell (SOFC) electrolyte supports.

· Composite materials: as fiber or whisker reinforced metal/ceramic matrix (such as brake pad composites).

The limitations of mullite ceramics are mainly difficult to process (high hardness leads to high cutting costs) and low toughness at room temperature, but they can be partially overcome by composite modification (such as introducing ZrO₂ for toughening). It is less used in the biomedical field, but high-purity mullite has potential research value in dental restoration.

Mullite Ceramic - Introduction & Material Parameters

Composition

Performance characteristics

Main Application Areas

Ceramic Information

Service Guarantee

Ceramic Display

Contact Us

Dongguan Mingrui Ceramic Technology Co., Ltd.

Yongzhou Mingrui Ceramic Technology Co.,Ltd.