Basic Info.
Material
99% Alumina, 95% Alumina
Density
3.65 - 3.95 G/Cme
Max. Working Temp.
1500 - 1700 C
Compressive Strength
2200 - 2500 Mpa
Flexural Strength
280 - 350 Mpa
Thermal Conductivity
18 - 30 W/M.K
Product Description
Properties of Ceramic Insulator Plate
(1). Excellent in electrical insulation;
(2). High hardness and wear/corrosion resistance;
(3). High working temperature;
(4). Good thermal shock resistance;
Alumina is the most popular ceramic material resulting from nearly endless availability in different purities, starting with approx. 92 % ending up with 99.99 % qualities and the specific material characteristics. Combining a medium level bending strength with excellent wear resistance, high hardness and relatively good thermal conductivity Alumina is versatile useable. Especially in electrical applications and high temperature operations the excellent insulating behavior and dielectric strength favor Alumina for use up to 1750 ° C.
Hardness is paired with high brittleness, therefore Alumina is not suited in highly loaded machinery applications. From time to time a customizing and modification in design-engineering can succeed.
1. Characteristics of Alumina include:
* Electrically insulating
* High thermal conductivity
* High strength and stiffness
* Available in a range of purities
* Excellent resistance to strong acids and alkalis at elevated temperatures
2. Applications of Alumina Ceramics
2.1 Plasma torch insulator
A stainless steel fabrication company needed a custom-made plasma torch, which called for a custom-made insulator with provision for cooling air flow. It had to be a precision fit in the housing, Here is the result of extrusion followed by grinding.
2.2 High Pressure Seal
This is a ceramic seal for a high pressure pump. The smaller component fits into the bevel in the larger ring, with the mating faces polished to a 50 nanometre Ra (N2) finish.
2.3 Heat Shield
A research laboratory in a multinational metals company needed a structural support for some instrumentation. The support needed to carry the weight of the instruments while shielding them from radiant heat. The solution: A precision machined disc, 170 mm in diameter with view ports.
2.4 Corrosion Resistant Liner
These liners are used in a plasma arc furnace operating at 1600 deg. Centigrade. The liners provide protection against hydrogen chloride vapour, far outlasting any metal that was tried. The outside diameter, the length and the step are machined to a precise fit in a metal sleeve.
2.5 High Power Insulators
These insulators are used in a high power, high voltage, radio frequency generator. The outside diameter is precision ground. Note the delicate thickness: 3 mm! Alumina was chosen for its excellent electrical properties under extreme conditions.
2.6 Wire Guides
High purity alumina is well known as an outstandingly hard and abrasion resistant material. So, when one of Australia's largest manufacturers of wire cable came to us for a set of alumina wire guides, we were not surprised. We were surprised when they said they needed 160 guides of a completely new design custom-made in two days! Thanks to our skilled staff and excellent diamond machining, the order was shipped in 28 hours.
2.7 Frictionless clutches
A company came to us looking for a material that could be used for clutch plates. The clutch could be stationary for days between uses, so any lubricating oil would drain away. The clutch would then burn out on start-up. We suggested highly polished alumina, which can run dry with no detectable wear after very heavy sliding loads. The coefficient of friction was as low as 0.03, so there was almost no change in friction when the oil finally arrived. The clutch was a complete success - but it did require enormous springs to get the normal force high enough to transmit the torque.
Characteristics |
Unit |
95 Al2O3 |
99 Al2O3 |
ZrO2 |
GPSi3N4 |
BN |
Glass Ceramic |
Crystal Structure |
- |
hexagonal |
hexagonal |
tetragonal |
hexagonal |
hexagonal |
- |
Color |
- |
white |
ivory |
white |
gray |
white |
white |
Density |
g/cm³ |
3.65 |
3.88 |
5.95 |
3.22 |
2.26 |
2.55 |
Water Absorption |
% |
0 |
0 |
0 |
0 |
0.0-1.0 |
0 |
Young's Modulus |
Gpa |
280 |
350 |
205 |
295 |
670 |
65 |
Vickers Hardness |
Gpa |
14 |
20 |
12 |
18-20 |
- |
- |
Flexural Strength |
Mpa |
280 |
300 |
900 |
650 |
51 |
100 |
Compressive Strength |
Mpa |
2000 |
2500 |
2200 |
2200 |
230 |
500 |
Thermal Conductivity |
W/(m•K) |
18-25 |
30 |
2.2 |
25 |
20 |
1.70 |
Thermal shock resistance |
ΔT(C°) |
220 |
180-200 |
280-350 |
450-650 |
>1500 |
25-100 |
Max. Working Temperature |
C° |
1500 |
1700 |
850 |
1200 |
960 |
800 |
Volume Resistivity |
Ω . cm |
>10^15 |
>10^14 |
>10^12 |
>10^14 |
10^13 |
10^16 |
Dielectric Constant |
- |
9.50 |
9.80 |
26 |
8.20 |
4.08 |
6.02 |
Dielectric Strength |
kV/mm |
16 |
22 |
- |
16 |
375 |
40 |
Address:
No. 153 Yuehua Road, Xiamen, Fujian, China
Business Type:
Manufacturer/Factory, Trading Company
Business Range:
Electrical & Electronics, Industrial Equipment & Components, Manufacturing & Processing Machinery, Metallurgy, Mineral & Energy, Textile, Tools & Hardware
Management System Certification:
ISO 9001, OHSAS/ OHSMS 18001
Company Introduction:
UNIPRETEC manufactures, develops and supply components made of technical ceramics, which include Al2O3 Alumina, BN Boron Nitride, SiC Silicon Carbide, Si3N4 Silicon Nitride, ZrO2 Zirconia...
With experience in research and development in technical ceramic materials, process development, manufacturing of precision components and small assemblies for the various applications for the Automotive, Aerospace, Oil & Fas Industries, Foundries, Food, Medical, Chemical etc. And also consulting & working with many customers and partners around the world, we welcome any opportunity related to above products from anyone who is interested in for development or sourcing high tech ceramic components from us.
If you need any further information, please do not hesitate to contact us online.