Alumina (Aluminium Oxide)

Description

Alumina is also known as aluminium oxide (Al2O3). Alumina ceramics are wear-resistant, corrosion-resistant, and have high hardness. They have a wide range of uses in various fields such as mechanical and electrical.

Features

High hardness
Light weight
Electrical insulation
Corrosion resistant
Wear-resistant

Applications

Wear-resistant block
Valve
Pump
Plungers
Seals
Bearings
Nozzle
Mechanical components and parts
High temperature protection tube
Other applications

GW Ceramics provides customized services

Properties

Mechanical Properties

	Colour	Density (g/cm³)	Mohs Hardness	Compressive Strength (Mpa)	Flexural Strength (Mpa)	Young’s modulus （GPa）	Fracture Toughness (MPa·m^1/2)	Poisson’s Ratio
95% Alumina	white	3.5-3.7	9	＞2000	＞255	320	3-4	0.23
97% Alumina	white	3.6-3.73	9	＞2050	＞255	330	3-4	0.23
99% Alumina	light yellow	3.75-3.9	9	＞2200	＞300	360	3-4	0.23
99.5% Alumina	light yellow	3.8-3.9	9	2000-2600	＞330	370	4-5	0.23
99.8% Alumina	light yellow	3.8-3.92	9	2000-2800	＞350	370	4-5	0.22

Thermal Properties

	Coefficient of Thermal Expansion (40-400°C) (× 10-6/℃)	Thermal Shock Resistance (℃)	Thermal Conductivity (W/m·K)	Maximum Operating Temperature (without load) (℃)
95% Alumina	6.5	200	24	1450
97% Alumina	7.1	200	25	1600
99% Alumina	7.3	220	29	1650
99.5% Alumina	8.3	220	32.3	1700
99.8% Alumina	8.5	220	26	1700

Electrical Properties

	Dielectric Constant (1MHz)	Dielectric Strength (kV/mm)	Volume Resistivity (25°C) (Ω·cm)
95% Alumina	8.9-9.2	8-8.7	＞10¹⁴
97% Alumina	9-9.2	8-9	＞10¹⁴
99% Alumina	9-9.7	8-9	＞10¹⁴
99.5% Alumina	9.7-9.9	8.7-9.4	＞10¹⁴
99.8% Alumina	9.7-9.9	8.7-9.4	＞10¹⁶

*The data in the charts show the properties of the ceramic materials.
*The above figures do not represent any commitment to the customer’s product.
*Due to differences in production processes and product forms, the final property data for ceramics may vary.