Mullit Ceramic Honeycombs Description
Mullit Ceramic Honeycombs are a structured ceramic material based on Mullite (3Al2O3-2SiO2), a silicate mineral derived from aluminium and silicon. This material exhibits high thermal stability, measured mechanical strength and chemical inertness according to standard tests. The honeycomb structure consists of interconnected channels or cells arranged in a regular hexagonal pattern, thereby providing a balance between low density, extensive surface area and quantifiable thermal and mechanical performance.
Specifications for Mullit Ceramic Honeycombs
Properties
|
Units
|
Test
|
Value
|
Physical
|
Chemical Formula
|
-
|
-
|
3Al2O3-SiO2
|
Density, ρ
|
g/cm3
|
ASTM C20
|
2.80
|
Colour
|
-
|
-
|
light brown
|
Crystal Structure
|
-
|
-
|
orthorhombic
|
Water Absorption
|
% @ R.T.
|
ASTM C373
|
0.0
|
Hardness
|
Moh's
|
-
|
8
|
Hardness
|
Knoop (kg/mm2)
|
Knoop 100g
|
1 450
|
Mechanical
|
Compressive Strength
|
MPa @ R.T.
|
ASTM C773
|
551
|
Tensile Strength
|
MPa @ R.T.
|
ACMA Test #4
|
103.5
|
Young's Modulus
|
GPa
|
ASTM C848
|
150
|
Modulus of Rupture (MOR)
|
MPa @ R.T.
|
ASTM F417
|
170
|
Poisson's Ratio, ν
|
-
|
ASTM C818
|
0.25
|
Fracture Toughness, KIc
|
MPa x m1/2
|
Kerbschlagbiegeversuch
|
2.0
|
Thermal
|
Max. Operating Temperature (* indicates inert atmosphere)
|
°C
|
Ohne Last kond.
|
1 700
|
Thermal Shock Resistance
|
ΔT (°C)
|
Abschrecken
|
300
|
Thermal Conductivity
|
W/m-K @ R.T.
|
ASTM C408
|
3.5
|
Linear Thermal Expansion Coefficient, αl
|
µm/m-°C (~25°C to ±1000°C)
|
ASTM C372
|
5.3
|
Specific Heat, cp
|
cal/g-°C @ R.T.
|
ASTM C351
|
0.23
|
Electrical
|
Dielectric Constant
|
1MHz @ R.T.
|
ASTM D150
|
6.0
|
Dielectric Strength
|
kV/mm
|
ASTM D116
|
9.8
|
Electrical Resistivity
|
Ω cm @ R.T.
|
ASTM D1829
|
1 013
|
Mullit Ceramic Honeycombs Chemical Composition
SiO2%
|
25-38
|
Al2O3%
|
50-65
|
MgO Content
|
<1.0
|
K2O+Na2O3%
|
<1.0
|
Fe2O3%
|
<1.5
|
Mullit Ceramic Honeycombs Applications
- Catalysts in automotive exhaust systems: The honeycomb structure provides an extensive surface for catalytic coatings, thereby facilitating the conversion of exhaust gases to compounds with reduced harmful content.
- Heat exchangers: They are used in high-temperature environments to transfer heat with minimal pressure drop, given that the large surface area and thermal stability of Mullite support effective performance.
- Gas burner media: In industrial burners, the honeycomb structure ensures uniform gas distribution and increases the combustion area, thereby contributing to improved combustion processes.
- Filtration: Mullit Ceramic Honeycombs serve as filters for hot gases or liquids. They withstand high temperatures and corrosive conditions as confirmed through standard tests and are applied in industrial filtration.
- Structural support and insulation: In furnaces and ovens, the honeycomb provides light structural support and insulation while maintaining stability at high temperatures.
Mullit Ceramic Honeycombs Packaging
Mullit Ceramic Honeycombs are handled carefully during storage and transportation to preserve the product quality in its original condition.