Properties

Units

Test

Value

Physical

Chemical Formula

–

–

Al₂O₃

Density, ρ

g/cm³

ASTM C20

3.7-3.97

Color

–

–

ivory/white

Crystal Structure

–

–

hexagonal

Water Absorption

% @R.T.

ASTM C373

0.0

Hardness

Moh’s

–

9

Hardness

knoop (kg/mm²)

Knoop 100g

2000

Mechanical

Compressive Strength

MPa @ R.T.

ASTM C773

2070-2620

Tensile Strength

MPa @ R.T.

ACMA Test #4

260-300

Modulus of Elasticity
(Young’s Mod.)

GPa

ASTM C848

394

Flexural Strength (MOR)

MPa @ R.T.

ASTM F417

310-379

Poisson’s Ratio, ν

–

ASTM C818

0.27

Fracture Toughness, K_Ic

MPa x m^1/2

Notched Beam Test

4.5

Thermal

Max. Use Temperature
(* denotes inert atm.)

ºC

No load cond.

1750

Thermal Shock Resistance

ΔT (ºC)

Quenching

200

Thermal Conductivity

W/m-K @ R.T.

ASTM C408

35

Coefficient of Linear Thermal Expansion, α_l

µm/m-ºC (~25ºC through ±1000ºC)

ASTM C372

8.4

Specific Heat, c_p

cal/g-ºC @ R.T.

ASTM C351

0.21

Electrical

Dielectric Constant

1MHz @ R.T.

ASTM D150

9.6

Dielectric Strength

kV/mm

ASTM D116

15

Electrical Resistivity

Ω cm @ R.T.

ASTM D1829

>10¹⁴

SiO₂%

50.9±1

Al₂O₃%

35.2±1

MgO%

13.9±1