high purity optical electronic corundum mullite ceramic machining structural parts OEM factory
Mullite Ceramics:
Mullite ceramic refers to a ceramic whose main crystal phase is mullite. Mullite is the only stable binary compound in the Al2O3-SiO2 system. The composition can vary from 3Al2O3·2SiO2 to 2Al2O3·SiO2, that is, the Al2O3 content can fluctuate within the range of 71.8-77.3 wt%. 3Al2O·2SiO2 is the stoichiometric composition and content of mullite.
Mullite Ceramics properties:
Mechanical properties
The mechanical properties of the high-purity mullite ceramic sintered body are determined by the ratio of Al2O3/SiO2 and the microstructure, especially the mullite ceramics with an Al2O3 content of 68%. The flexural strength at 1300 °C is 570 MPa, and the fracture toughness Kic is up to 5.7MPa.Nm, which is 1.6 times higher than normal temperature. This temperature increase, strength and toughness not only do not attenuate but increase greatly. In addition to SiC, it is unique in the existing high-temperature ceramic materials, which is also high. Pure mullite ceramics are excellent properties as high temperature materials.
Optical performance
Although the mullite crystal is not a cubic crystal system, it is only an orthorhombic system, but due to the small birefringence of light (only 0.012), a ceramic material having a certain transparency can be obtained under certain conditions. High-purity ultrafine powder prepared by alkoxide hydrolysis method, transparent mullite porcelain can be obtained by vacuum sintering at 1750 °C.
Data Sheet↓
Item | Unit | Typical Values |
Physical Properties |
Color | White/Ivory |
Raw material | / | Alumina, silicon oxide |
Gas permeability | 0 |
Water Absorption | 0 |
Mechanical Properties |
Rockwell Hardness(45N) | R45N | 40 |
Vickers Hardness (Load 500g) | Gpa(Kg/mm²) | 11.5(1175) |
Flexural Strength(20°C) | Mpa | 108 |
Compressive Strength(20°C) | Mpa | 488 |
Modulus of Elasticity(25°C) | Gpa | 65 |
Thermal Properties |
Thermal Conductivity(25°C) | W(m.K) | 1.71 |
Thermal Expansion Coefficient | 10-7/ºC | 5.5 |
Thermal Shock Resistance | △T°C | 200 |
Maximum Use Temperature | °C | 1200 |
Electronic Properties |
Dielectric Constant | Er | 3.5-3.7 |
Volume Resistivity(20°C) | Ω.cm | 1×1019 1×1015 |
Application :
Refractory
High temperature engineering materials
Electronic packaging material
Optical material