Ferro-Ceramic Grinding Inc. machines over 15 different materials
Mullite
Mullite is a favorite material for many because of its numerous qualities—mainly its affordability and thermal shock resistance. With its durable structure, mullite is an ideal material for machining, making mullite machining a fairly straightforward and simple process.
Some other advantageous mullite ceramic properties include its oxygen resistance and excellent insulation quality. Although it’s quite durable, there are other materials that with superior mechanical properties, so mullite is typically used for more simple components and applications.
Mullite Properties
Mullite is an excellent structural material due to its high temperature stability, strength, and creep resistance. Creep resistance refers to a material’s resistance to degradation over a long period of exposure to significant stress. Mullite also has a low dielectric constant and high electrical insulation capabilities, which is why it’s a popular choice as an insulator.
There are many applications for mullite, but some common uses include Kiln Furniture, furnace center tube, heat exchange parts, heat insulation parts, and rollers.
If you’re interested in learning more about mullite and mullite machining, get in touch with our expert staff at Ferro-Ceramic.
| Properties | Units | Test | Value |
|---|---|---|---|
| Physical | |||
| Chemical Formula | - | - | 3Al2O3-SiO2 |
| Density, r | g/cm3 | ASTM C20 | 2.80 |
| Color | - | - | tan |
| Crystal Structure | - | - | orthorhombic |
| Water Absorption | % @R.T. | ASTM C373 | 0.0 |
| Hardness | Moh's | - | 8 |
| Hardness | knoop (kg/mm2) | Knoop 100g | 1450 |
| Mechanical | |||
| Compressive Strength | MPa @ R.T. | ASTM C773 | 551 |
| Tensile Strength | MPa @ R.T. | ACMA Test #4 | 103.5 |
| Modulus of Elasticity (Young's Mod.) | GPa | ASTM C848 | 150 |
| Flexural Strength (MOR) | MPa @ R.T. | ASTM F417 | 170 |
| Poisson's Ratio, u | - | ASTM C818 | 0.25 |
| Fracture Toughness, KIc | MPa x m1/2 | Notched Beam Test | 2.0 |
| Thermal | |||
| Max. Use Temperature (* denotes inert atm.) | ºC | No load cond. | 1700 |
| Thermal Shock Resistance | DT (ºC) | Quenching | 300 |
| Thermal Conductivity | W/m-K @ R.T. | ASTM C408 | 3.5 |
| Coefficient of Linear Thermal Expansion, al | mm/m-ºC (~25ºC through ±1000ºC) | ASTM C372 | 5.3 |
| Specific Heat, cp | cal/g-ºC @ 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 | Wcm @ R.T. | ASTM D1829 | 1013 |