Topics
Covered
Background
Sapphire
Advantages
of Sapphire
Applications
of Sapphire
Properties
of Sapphire
Background
Goodfellow
Ceramic & Glass Division are
an award-winning company who supply specialist glass and ceramics for
scientific and industrial use.
Goodfellow
Ceramic & Glass Division aim
is to understand your application and then supply the most appropriate
materials or components to meet your needs.
Our
technical staff are qualified in glass technology and materials science
and can, therefore, provide impartial advice and full technical support
for your projects.
Sapphire Glass
Sapphire can offer the ideal
solution for applications where standard glass and technical ceramics
are not sufficient. Superior physical, chemical and optical properties
allow sapphire to be used in demanding conditions.
Sapphire is transparent, single
crystal aluminium oxide. Sometimes, particularly for sapphire balls, a
slight trace of chromium oxide is added which gives it a “ruby” colour.
The material can be made in different ways which affects the
properties, particularly optical properties, and the shapes which can
be manufactured.
Advantages of Sapphire
The
advantages of sapphire include:
- Excellent optical characteristics, UV to IR
- High wear and scratch resistance
- High operating temperature (1800°C)
- Chemically inert
- High strength
- High electrical resistance
- High thermal conductivity
Applications of Sapphire
Applications
Applications of sapphire include:
- Optics
- Engineered components
- Substrates
- High pressure windows
- Precision spheres
Properties of Sapphire
Table 1. Typical
properties of sapphire.
| |
Property |
Units
|
Value
|
| General |
Chemical Formula |
n/a
|
Al2O3
|
| Density |
g/cm3
|
3.98
|
| Mechanical |
Compressive Strength |
MPa
|
2000
|
| Flexural strength |
MPa
|
480-900
|
| Young's Modulus |
GPa
|
350
|
| Thermal |
Max. Use Temperature |
°C
|
1800
|
| Thermal Conductivity |
W/m.K
|
40
|
| Co-Efficient of Linear Expansion |
10-6/°C
|
8.0
|
| Electrical |
Volume Resistance |
ohm.cm
|
1014
|
| Dielectric Constant |
|
9.4-11.5
|
| Dielectric Strength |
kV/mm
|
48
|
Note: Sapphire is anisotropic, i.e. some properties are not
the same in all directions.
Figure 1. Transmission
curve for 1mm sapphire (including surface reflection look).
Properties
of sapphire shown are typical values,
they are not absolute material properties, and should be used for
guidance only. It is recommended that materials and components are
tested for their suitability for a specific application.
Source: Goodfellow Ceramic & Glass Division
For more information on this source, please visit Goodfellow
Ceramic & Glass Division