Alumina ceramics (Al2O3), also known as corundum, is one of the most widely used ceramic materials in the industrial sector. Renowned for its exceptional hardness,
high-temperature resistance,and electrical insulation properties, alumina ceramics also boasts excellent thermal conductivity, chemical resistance, and wear resistance,
coupled with an extremely low thermal expansion coefficient.These properties make it ideal for use in military, aerospace, semiconductor manufacturing, energy,
chemical industries, and various equipment components that operate under harsh conditions.
The purity of alumina ceramics varies and should be selected based on specific application needs. The most common purity levels are 95%, 99%, and 99.7%, with higher purity correlating to enhanced performance.
Below is a comparison of the mechanical, thermal, and electrical properties of alumina ceramics at different purity levels:
properties | 95% Al2O3 | 99% Al2O3 | 99.7% Al2O3 | ZTA |
Colour | White | Pale Yellow | Light Yellow | White |
Density | 3.72 g/cm³ | 3.9 g/cm³ | 3.92g/cm³ | 4.3g/cm³ |
Hardness Mohs | 9 | 9 | 9 | 14.4 |
Tensile Modulus | 320 gp | 360 gp | 390 gp | |
Poisson's Ratio | 0.22 | 0.23 | 0.23 | 0.23 |
Flexural Strength | 300 MPa | 350 MPa | 380 MPa | 600 Mpa |
Compressive Strength (25℃) | 2400 MPa | 2500 MPa | 2500 MPa | 2500Mpa |
Fracture Toughness | 4.00 MPa·m½ | 4.00 MPa·m½ | 5.40 MPa·m½ | 4.80 MPa-m½ |
Weibull Modulus | 7-8 | 9-10 | 9-10 |
properties | 95% Al2O3 | 99% Al2O3 | 99.7% Al2O3 | ZTA |
Specific Heat Capacity | 0.880 J/g·°C | 0.880 J/g-°C | 0.900 J/g-°C | 0.800 J/g-°C |
Thermal Conductivity | 25.0 W/m·K | 26.5 W/m-K | 30W/m-K | 28W/m K |
CTE, linear (20.0-400°C) | 7.50 µm/m·°C | 7.5 µm/m·°C | 7.50 μm/m·°C | 7.50 μm/m·°C |
CTE, linear (20.0-1000°C) | 8.1 µm/m·°C | 8.20µm/m·°C | 8.50 μm/m·°C | 8.20µm/m·°C |
Max. Service Temp. Air | 1450°C | 1550℃ | 1600 | 1650 °C |
properties | 95% Al2O3 | 99% Al2O3 | 99.7% Al2O3 | ZTA |
Volume Resistivity (400°C) | >= 1.00×10^12 ohm·cm | 1.00×10¹⁴ ohm·cm | 1.00×10¹⁴ ohm·cm | 7.78 × 10^9 ohm-cm |
Dielectric Constant (1e+6 Hz) | 9.5 | 9.6 | 10 | 12.2 |
Dielectric Strength | 10-20 kV/mm | 20-25 kV/mm | 30.0-43 KV/mm | 50 V/mm |
Dielectric Loss Index (9.00e+9 Hz 0.0010) | 0.001 | 0.001 | 0.001 | 0.001 |
Note: The data presented is based on laboratory conditions and may vary in real-world applications. It is for reference only.
The Alumina Ceramic Manufacturing Process involves several key stages:
1 Powder Preparation: Ensures the finest quality material for ceramic production.
2 Forming Methods (Green Body): Techniques include dry pressing, injection molding, tape casting, hot pressing, and isostatic pressing.
3 Sintering Techniques:
*Conventional high-temperature furnace sintering
*Hot isostatic pressing (HIP)
*Microwave sintering
4 Machining:
*CNC machining
*Grinding
*Cutting
5 Surface Treatment: Various finishing methods depending on the final application.
6 Quality Inspection: Advanced tools like coordinate measuring machines (CMM) and image measurement instruments ensure high standards.
Alumina Company
Founded in 2016,WEIERT Ceramics is a leading manufacturer of technical ceramics, not a trading intermediary. We offer both standard and custom-engineered ceramics, including crucibles, and pre-fabricated ceramic tubes and plates. Our capabilities include producing ceramic plates up to 1.6 x 0.53m and tubes with diameters less than 80mm, designed for secondary processing to meet specific customer needs. Our commitment is to provide the most competitive pricing and service through innovation in technology and management.