CoorsTek

Home

+1 303 271 7100

Contact

Alumina

Family Overview

Aluminas (aluminum oxide, Al2O3) are the most commonly used technical ceramics due to their generally useful properties and good price/performance ratio. Alumina ceramics are commonly subdivided according to their alumina content ranging from 80% to more than 99%. Higher purity alumina demonstrates enhanced wear and corrosion resistance — creating a continuous scale of various alumina grades, compositions, and performance.

Aluminas are used in both general use and specialized applications. A grade is selected to fit the application environment. Alumina compositions and microstructures can be formulated to meet the specific performance requirements of more demanding applications. 

  • General use
  • Wear resistance
  • Electrical insulator
  • Dielectric strength
  • Low dielectric loss

Ceramic Expertise

CoorsTek has developed over 100 unique alumina compositions, optimized for specific application requirements. Let our experts help you determine the best-fit material for your application.

Brochure Downloads

Download the Advanced Alumina brochure

Download the Advanced Alumina for Semiconductor brochure

Alumina properties

 

    AD-94 AD-96 FG-995 AD-995 PLASMAPURE
AD-998
PLASMAPURE-UC
ALUMINA
Properties Units Nom. 94% Al2O3 Nom. 96% Al2O3 Nom. 98.5% Al2O3 Nom. 99.5% Al2O3 Nom. 99.8% Al2O3 Nom. 99.9% Al2O3
Density g/cm³ 3.70 3.72 3.80 3.90 3.92 3.92
Color WHITE WHITE WHITE IVORY IVORY IVORY

4-PT Flexural Strength
(MOR) 
(20° C)

MPa
(psi x 10³)
308 343 298 300 320 360
Elastic Modulus
(20° C)
GPa
(psi x 106)
303 303 350 370 380 386
Poisson’s Ratio
(20° C)
0.21 0.21 0.22 0.22 0.22 0.22
Compressive Strength
(20° C)
MPa
(psi x 10³)
2103 2068 2500 2600 2650 2700
Hardness
(Knoop 1000gm)
GPa
(kg/mm²)
11.5 11.5 13.7 14.1 14.1 14.5
Fracture Toughness
(K(I c))
MPa m1/2 4 - 5 4 - 5 4 - 5 4 - 5 4 - 5 4 - 5
Thermal Conductivity
(20° C)
W/m 22.4 24.7 27.5 30.0 31.0 33.0
Coefficient of Thermal Expansion (25-1000°C) 1x10-6/°C 8.2 8.2 8.2 8.2 8.2 8.2
Specific Heat
(100° C)
J/kg*K 880 880 880 880 880 870
Dielectric Strength
(6.35mm)
ac-kV/mm
(ac V/mil)
8.3 8.3 8.7 8.7 8.7 8.7
Dielectric Constant
(1 MHz)
25° C 9.1 9.0 9.6 9.7 9.8 9.8
Dielectric Loss (tan delta)
(1 MHz 25° C)
25° C 0.0004 0.0002 0.0002 0.0001 < 0.0001 <0.0001
Volume Resistivity
(25° C)
ohm-cm >1014 >1014 >1014 >1014 >1014 >1015
(500° C) ohm-cm 4 x 109 4 x 109 2 x 1010 2 x 1010 2 x 1011 1 x 1012
(1000° C) ohm-cm 5 x 105 1 x 106 2 x 106 2 x 106 2 x 107 1 x 107

CONNECT WITH COORSTEK