Alumina Ceramic Companies and Suppliers

Alumina Ceramic

Alumina ceramics are products made from the chemical compound with the same name, alumina ceramic. Alumina ceramic, also known as aluminum oxide, is a combination of aluminum and oxygen. It occurs naturally, most often as corundum, as a crystalline form of the compound that, when gem quality, manifests as sapphire or ruby. Alumina ceramic is extremely hard and durable, resistant to compressive strength, resistant to weathering, resistant to chemicals, electrically insulating, highly dense and stiff and incredibly thermally conductive. In fact, it is up to twenty times more thermally conductive than the majority of other oxides. In addition, it is quite cost effective.

Quick links to Alumina Ceramic Information

• Materials in Alumina Ceramics
• Phases and Grades of Alumina
• Alumina Ceramic Manufacturing Processes
• Applications of Alumina Ceramics
• Engineering Properties of Alumina Ceramics

Materials in Alumina Ceramics

Before coming any number of useful products, all alumina ceramics begin as granular powder. This powder can be used alone, but, as is usually the case, it can also be mixed with other substances and stabilizers, selected based on the way or ways that they can improve the alumina. A common additive, zirconia, for instance, is added to the mix in order to increase the ceramic’s fracture toughness. Examples of other additives include manganese oxide, titania, silica, copper and brass. Note that, when it is in its natural state, alumina is white, but when mixed with additional substances, it frequently changes color. For example, alumina ceramics that are around 96% pure are typically brown in color, while those alumina ceramics that are less pure, around 88% for instance, are usually pink.

Phases and Grades of Alumina

In addition, alumina is categorized by phase and grade. These categorizations help manufacturers understand the properties of a particular aluminum oxide and how it might benefit an application. For instance, one of the most commonly used aluminum oxides is smelter grade alumina, also known as metallurgical grade alumina, which is non-toxic, non-flammable and non-hazardous. This stable and low maintenance alumina is the nearly exclusively selected grade of alumina aluminum metal production. Other alumina grades include high purity alumina, calcined alumina, fused alumina, low soda alumina, tabular alumina and reactive alumina. High-purity alumina is defined as any alumina that has a purity of 99.99% or above. It is used to manufacture instrument windows, synthetic gemstones and laser tubes and other laser components. Next, calcined alumina is created when aluminum hydroxide is heated above 1100. Calcined alumina is known to improve the performances of both monolithic and shaped refractories. Fused alumina, which is formed in an electric arc furnace, is used in a crushed form. Low soda alumina is defined as any alumina that has a soda content of <0.1% by weight. It is used primarily with and as electronic and electrical components. Tabular alumina, which is recrystallised or sintered a-alumina, is used in both unshaped and shaped refractories for waste incineration, petrochemical, glass, cement steel and foundry applications. Finally, reactive alumina is fairly pure, small crystal alumina. It is used in the creation of high-performance refractories that require consistent placement characteristics and defined particle packing.

Alumina Ceramic Manufacturing Processes

After an alumina formula has been selected and finalized, it is further processed and manufactured using any number of processes, such as injection molding, extrusion, pressing or slip casting. The only processes through which alumina ceramic products cannot be created are forging, stretching, blowing and thermoforming; all of these processes would put the alumina at risk of becoming brittle, a state that would likely lead to breakage.

Applications of Alumina Ceramics

Finished alumina ceramics are highly useful and exhibit high performance levels and durability. Some of the most common products in which alumina ceramics are found include: grinding media, paint, plastic, sunscreen, blush, lipstick, nail polish and other cosmetics, glass, composite fiber and sodium vapor lamps. They serve roles as gas stream purifiers, sandpaper abrasives, ceramic eyes on fishing rods, coating suspensions in fluorescent lamps, material in birth control pills, material in hip replacements, electrical insulators, thermocouples, thread guides, wear components, tunnel barriers during the fabrication of superconductors and more. Alumina ceramics are particularly useful in the creation of insulation for high heat furnaces. Alumina ceramics-based insulation, which are often mixed with varying percentages of silica, can be made in many forms, including in the forms of bricks, loose fibers, blankets and boards. Alumina ceramics also make excellent spark plug insulators.

These qualities make alumina ceramics ideal for a wide variety of industrial and commercial applications, including: automotive and aerospace engineering, medical instrument fabrication, prosthetic limb creation, ballistic ceramic armor creation, metalizing, seal ring fabrication, welding, plating and the pre-finishing of wood flooring.

Alumina is an amazingly diverse product with breathtaking prominence in the world. To find out how alumina ceramics might serve you, contact a reputable ceramic manufacturer.

Engineering Properties of Alumina Ceramics*

*All properties are room temperature values except as noted.

The data presented is typical of commercially available material and is offered for comparative purposes only. The information is not to be interpreted as absolute material properties nor does it constitute a representation or warranty for which we assume legal liability. User shall determine suitability of the material for the intended use and assumes all risk and liability whatsoever in connection therewith.