Special Machining Ceramic Parts With Temperature Resistance And
Anti Dirt
The manufacturing route for advanced ceramics include:
consolidation of the powder, green machining of the compacted
powder, sintering and finally, when required diamond grinding.
>>> Green Machining
This technique is commonly applied to as-pressed parts which are
still in a chalky condition. Common metalworking machines are used
to machine the part in this soft condition, as greater material
removal rates are possible than by post-sintering operations such
as diamond grinding. As-fired green machined components are subject
to tolerances of approximately +/- 1%. To achieve tighter
tolerances, diamond grinding must be employed.
>>> Sintering
The compacted and machined components are fired or “sintered” at
temperatures approaching 1800C°. During this operation, the powder
particles bond together and component shrinks by 15%-35%.
>>> Diamond Grinding
Following sintering, the ceramic (now in its ultra-hard state) is
machined using diamond grinding techniques which, together with
lapping and polishing, enable tight tolerances and smooth surface
finishes to be achieved. However, diamond grinding is relatively
expensive, so if as-fired tolerances are acceptable, the overall
cost of the component is reduced.
Aluminium Oxide Ceramics
Aluminum Oxide, also known as alumina, is a hard wearing advanced
technical ceramic material frequently used in a wide variety of
industrial applications. Once fired and sintered, it can only be
machined using diamond-grinding methods. It features high hardness
and wear resistance, low erosion levels, high temp. resistance,
corrosion resistance, and bioinertness. Additionally, it can be
highly polished, making it useful for a wide range of applications.
Frequently used alumina's purity is from 90% to 99.7%.
Main Properties of Alumium Oxide Ceramics
| Type | Unit | A95 | A99 |
| Alumina Content | % | 92 - 96 | 99 - 99.7 |
| Density | g/cm3 | 3.65 | 3.88 |
| Color | - | white | ivory |
| Water Absorption | % | 0 | 0 |
| Young Modulus | Gpa | 280 | 350 |
| Vickers Hardness | Gpa | 14 | 20 |
| Compressive Strength | Mpa | 2000 | 2500 |
| Flexural Strength | Mpa | 280 | 300 |
| Thermal Conductivity | W/m.K | 18 - 25 | 30 - 35 |
| Thermal Shock Resistance | Δ(°C) | 220 | 180 200 |
| Max. Working Temp. | °C | 1500 | 1700 |
| Volume Resistivity | Ω ·cm | > 10^15 | > 10^14 |
| Dielectric Constant | - | 9.50 | 9.80 |
| Dielectric Strength | kV/mm | 16 | 22 |
Industrial Ceramic Intriduction
Aluminium Oxide, Al2O3 is the most widely applied and cost
effective technical ceramic material. It offers a combination of
superior mechanical strength and electrical properties, wear
resistance and corrosion resistance. The maximum working
temperature is up to 1700 °C with relatively high thermal
conductivity. It is also an electrically insulating material with a
high electrical resistivity. The good corrosion resistance makes it
insoluble in water and slightly soluble in strong acid and alkaline
solution.
Company Introduction
Mingrui ceramic manufacture and provides alumina ceramic components
for a wide range of application like Mechanical Equipment,
Electronic & Electrical, Oil Drilling, Medical, Chemical Industry
etc. According to actual application and customer's requirement,
the purities vary from 95%-99.7% and the forming methods will be
different. The forming methods applied in our plant include dry
pressing, isostatic pressing, injection moulding, extrusion
moulding. With experienced engineers and talented workers, we are
confident to offer high quality, high precision, complex components
for customers worldwide.
