Aluminium Oxide, Al2O3 is a major engineering material. It offers a combination of good mechanical properties and electrical properties leading to a wide range of applications.

Alumina can be produced in a range of purities with additives designed to enhance properties. A wide variety of ceramic processing methods can be applied including machining or net shape forming to produce a wide variety of sizes and shapes of component. In addition it can be readily joined to metals or other ceramics using metallising and brazing techniques.

Alumina based ceramics are by far the largest range of advanced ceramics made by Unipretec Ceramics. Due to the important combination of properties, we have thoroughly researched the behaviour and characteristics of our Alumina products to give you the best possible component.

Unit

95% Al2O3

99% Al2O3

ZrO2

GP-Si3N4

Color

-

white

ivory

white

gray

Density

g/cm³

3.65

3.88

5.95

3.22

Water Absorption

%

0

0

0

0

Young's Modulus

Gpa

280

350

205

295

Vickers Hardness

Gpa

14

20

12

18-20

Flexural Strength ( at R.T. )

Mpa

280

300

900

650

Compressive Strength ( at R.T. )

Mpa

2000

2500

2200

2200

Thermal Conductivity ( at R.T. )

W/(m.K)

18-25

30

2.2

25

Thermal Shock Resistance

ΔT(°C)

220

180-200

280-350

450-650

Max. Working Temperature ( at R.T. )

°C

1500

1700

850

1200

Volume Resistivity ( at R.T. )

Ω.cm

>10^15

>10^14

>10^12

>10^14

Dielectric Constant  (1 MHz at R.T. )

-

9.50

9.80

26

8.20

Dielectric Strength

kV/mm

16

22

-

16

Electrical Eingeering
- electrical feedthroughs and insulating tubes for vacuum equipment- inspection equipment for semiconductors/photovoltaics
- apparatus for research and development (accelerator technology)
- high-quality electronics
- probe technology
- sensor housings
- onshore-/offshore-technology (high pressure)

Mechanical Engineering
- pistons for dosing pumps
- plungers for high pressure pumps
- shaft protection sleeves
- plain bearings and roller bearings
- shaped parts for demanding wear resistance
- drawings cones and guides for the wire industries
- nozzles, guides, pressing dies...

High Temperature Technology
- tubes and insulating rods for protection and insulation of tehrmocouples and for gas inlet and exhaust tubes
- externally-grooved tubes and special heating tubes for construction of electrically heated furnaces
- diffusion tubes for the semiconductor industry
- laborator ware, e.g. Crucibles, boats, combustion trays and plates for heat treatment and melting at high temperatures

Medical Applications
- components of surgical instruments
- surgical cutting
- piezo ceramics in blood flow measurement sensors
- ceramic feed-thru for internal bone growth stimulators
- medication infusion pumps
- ceramic injection moulding produces small high precision implants
- joint replacement

>>> Q: What are advanced ceramics?
Advanced ceramics - also referred to as engineering, structural or technical ceramics - have been processed to be very pure and, in general, have superior properties to unrefined ceramics. Many are man-made, i.e. they do not occur naturally, e.g. silicon nitride, and their properties can be enhanced to produce very high strength at high temperatures, good corrosion resistance, etc.

>>> Q: What types of ceramic do you supply?
Alumina in purity from 90% to 99.7%, yttria stabilized zirconia (Y-PSZ), hot pressed boron nitride, machinable glass ceramic, boron carbide, silicon nitride, mullite and cordierite.

>>> Q: Can I machine the ceramics myself?
The harder ceramics like alumna and zirconia will require diamond tooling but other materials like Machinable Glass Ceramic and Hot Pressed Boron Nitride can be machined. To get the right result it does take time, experience and semi-specialised tooling but it can be done and many of our customers take advantage of this when they need extremely fast solutions in-house.

>>> Q: Do you ship internationally?
Yes, we can ship to virtually anywhere in the world. Typically we will use international express, like DHL, UPS, TNT, FEDEX, EMS... We can also arrange shipments on your own courier account if you prefer to take this route.

>>> Q: Can I get a sample or purchase a small quantity?
Yes, we are happy to supply small samples of material for you to test. We can also supply prototype quantities through to volume production to suit your needs.

>>> Q: How long will it take for you to send me a quote?
This depends totally on the complexity of your requirements. For simple items such as bars and rods, we can generally supply a quotation within 24 hours.

>>> Q: What's the delivery time?
For our standard products, like ceramic protection tubes and insulating rods, delivery time is normally 7 working days. For hot pressed boron nitride and machinable glass ceramic, it's about 10 working days. For customized products made of alumina, zirconia, boron carbide and silicon nitride, total producing time is about 30 working days.