Alumina

Alumina or 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 supplied by Venture Scientific®. 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.

Venture Scientific® offer a variety of alumina products, including Crucibles, tubes and plates. We are also able to supply custom shapes. Our Alumina products have a maximum operating temperature of 1700°C, making them ideal for high temperature applications.Venture Scientific® supply Oxide Ceramic components of Alumina, Zirconia, and their Composites by Powder Compaction, Injection Molding, ISO-static Pressing, Slip Casting.

Our high purity (Al2O3 content > 99%) ceramics are purpose built to perform across a wide range of high temperature applications. We use recrystallized alumina in the production of our crucibles as the material offers impressive thermal shock resistance, this is due to the sintered grain size (between 2-4 microns). Our high purity alumina shows considerable resistance to chemical attack due to the lack of glassy phases that tend to determine corrosion resistance.

The electrical and dielectrical properties of the material generally improve with increased purity. Electrical resistance is greatest and dielectrical loss factor is lowest in materials of highest alumina content.

Typical alumina characteristics include:

• Good strength and stiffness
• Good hardness and wear resistance
• Good corrosion resistance
• Good thermal stability
• Excellent dielectric properties (from DC to GHz frequencies)
• Low dielectric constant
• Low loss tangent

Typical alumina applications include:

• Laboratory analysis
• Metal and nonmetal material sample melting
• High temperature (like metal processing, glass melting, rapid thermal cycling, gemstone purification for jewelry industry)
• Metallurgy
• Chemical Industry
• Electronic substrates
• Thermocouple tubes
• Electrical insulators
• Grinding media
• Threadguides
• Wear components

MATERIAL PROPERTIES

Please note that the information set forth herein is offered for comparison only, and is not to be construed as absolute engineering data or constituting a warranty or representation for which we assume legal responsibility.

• DATA MEASUREMENTS – All data measurements are typical and made at room temperature unless otherwise noted.The Values are obtained from standard bars & cubes, Data on other shapes shall differ, the data should not be taken as a specification but for general guidance only.

• THERMAL SHOCK RESISTANCE – Tests are run by quenching samples into water from various elevated temperatures. Temperature change rate should not exceed 150oC/Hr. Alumina crucibles are sensitive to thermal shock. Try to warm up the furnace chamber slowly. So that the crucibles can be evenly heated to reduce the impact of thermal shock.

• CHEMICAL RESISTANCE – Although all alumina and zirconia ceramics are highly resistant to chemical attack, it is recommended that specific applications are discussed with us to ensure optimum ceramic selection.

CHEMICAL COMPOSITION