SGJ Ceramic vacuum high voltage components Re-crystallised alumina spacers Ceramic Filament Holder Block
Alumina Manufacturing Description:
Alumina Ceramics can be produced in a wide range of purities with additives designed to enhance its properties. Typical purities range from 85 to 99.7% although Precision Ceramics generally work over 99.7% material.
It can be injection molded, die pressed, isostatically pressed, slip cast and extruded. Once fired and sintered, it can only be machined using diamondgrinding methods but prior to sintering advanced green and biscuit machining techniques developed by Precision Ceramics allow more complex components to be manufactured using traditional machining methods. In addition Alumina can be readily joined to metals or other ceramics using metallising and brazing techniques.
Alumina can be machined in green, biscuit, or fully dense states. While in the green or biscuit form it can be machined relatively easily into complex geometries. However, the sintering process that is required to fully densify the material causes the alumiuna body to shrink approximately 20%. This shrinkage means that it is impossible to hold very tight tolerances when machining alumina pre-sintering. In order to achieve very tight tolerances, fully sintered material must be machined/ground with diamond tools. In this process a very precise diamond coated tool/wheel is used to abrade away the material until the desired form is created. Due to the inherit toughness and hardness of the material, this can be a time consuming and costly process.
Precision Ceramics specialises in tight tolerance, highly complex work and has extensive in-house machining facilities - including 4th & 5th axis machining centres, drilling, grinding, milling, polishing, sawing, tapping, threading and turning - to enable us to manufacture Alumina components to the highest specifications.
Precision Ceramics is your Alumina machining specialist for your technical ceramic prototyping & manufacturing needs; we are always happy to use our many years of advanced ceramics experience to provide advice on materials, design, and application. If you would like to buy Alumina plates, rods, tubes or custom machined components, please contact SGJ for more details.
Alumina Electrical Ceramics
Alumina electrical ceramics have low dielectric constant, low dielectric loss, high insulation strength, high volume resistivity, good bending strength, high stability, high compressive strength and good cold and hot shock resistance. It is widely used in temperature controller, insulation parts, thermal equipment, electric heating equipment, iron structure building, shipbuilding and so on. Alumina is the most cost effective and widely used material in the family of engineering ceramics. Extremely High Purity, Temperature & Strength; Excellent Corrosion, High Strength, Wear Resistant, Electronic Insulating, Structural & Metalizing, Porous, Easily Degassed & Machinable. The raw materials from which this high-performance technical grade ceramic is made are readily available and reasonably priced, resulting in good value for the cost in fabricated alumina shapes.
Glazed Alumina Ceramics is a kind of material based on alumina, which is used in thick film integrated circuits. Alumina ceramics have good conductivity, mechanical strength and high temperature resistance. Alumina ceramics are widely used. Because of its superior performance, it has been widely used in modern society to meet the needs of daily use and special performance.
SGJ Alumina Ceramic Features:
• Excellent electrical insulation properties
• High compressive and dielectric strength
• High hardness and mechanical strength
• High thermal conductivity and thermal shock resistance
• Low density
• Resistant to strong acid and alkali attack at high temperatures
• Transparent to microwave radio frequencies
• Very specific thermal conductive and thermal expansion rates
• Wear and abrasion resistant
SGJ 96% alumina is an easily metallisable ceramic composition:
This material SGJ 96% alumina material is an excellent electrical insulator that can be metallised to facilitate high-temperature brazing of assemblies. This material features:
- Very high volume resistivity
- Low loss, constant high dielectric
- High density, non-porous and vacuum tight
- Resists abrasive wear and chemical attack
The fact that this material can be metallised makes this a good choice for many ceramic to metal or brazed assemblies such as high-vacuum systems, laser equipment (gas, solid-state and waveguide), X-ray tubes and electron microscopes, microwave windows and insulators in medical and scientific equipment.
SGJ 96% Alumina Ceramic Data Sheet:
|Thermal Conductivity||g. cal/cm-sec-ºC||0.049|
|C.T.E.||In/in/ºC x 10-7||75|
|Max. Working Temp.||ºC||1600|
|Dielectric Strength||D.C. Volts/Mil.@0.11''thick||230|
|Volume Resistivity||0hm/cm3 x 1012||2.0|
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