materials

Alumina

Alumina, or Aluminum Oxide, is the one most prolific ceramic materials used in technical manufacturing, with a myriad of exceptional properties ranging from corrosion resistance and dielectric strength, to hardness and mechanical properties, to thermal and electrical insulation.

5.0

Relative Cost of Material

6.0

Machining Degree of Difficulty

Summary

Alumina, or Aluminum Oxide (Al203), is the one most prolific ceramic materials used in technical manufacturing, with a myriad of exceptional properties ranging from corrosion resistance and dielectric strength, to hardness and mechanical properties, to thermal and electrical insulation. It comes in a number of purities and is available in many forms, making it a frequent choice across many different industries. 

One of the major limiting factors in Alumina component manufacturing is the high degree of difficulty that most manufacturers have with this material. While low-toleranced components can be isopressed prior to firing, machining Alumina after firing requires specific machining techniques, tooling, and strategies that can make complex geometries nearly impossible for most manufacturers. As an industry leader in Alumina machining, Mindrum Precision has been machining tight-toleranced components in a post-fired state has been a core competency at Mindrum Precision for decades. We have made components and assemblies for a massive number of aerospace and defense programs, including many NASA missions throughout the solar system, as well as for medical, semiconductor, fiber optic, and research applications. Click here for our contact information or to request a quote, and we will show you why more engineers are trusting us with their mission-critical needs.

Applications

Alumina is used in a variety of applications, from being one of the preferred materials for high-performance insulators, spacers, and heat sinks, to use in medical devices, mounts and isolators in space-based projects, and many other applications in extreme environments. Alumina is used in everyday applications like spark plugs or abrasion-resistant tiles, and Alumina components are found in almost every industry. Alumina’s impressive technical profile and relatively low material cost make it ideal for many large- and small-scale technical applications, and we at Mindrum Precision look forward to bringing your Alumina component design off of the drawing board and into reality.

 

Properties

Material PropertyAlumina
Density (g/cm^3)3.92
Hardness (Knoop)2100
Tensile Strength (MPa)272
Modulus of Elasticity (GPa)370
Flexural Strength (MPa)340
Compressive Strength (MPa)2650
Poisson's Ratio.22
Dielectric Strength (ac-kV/mm)8.7
Dielectric Constant (@1MHz)9.8
Volume Resistivity (ohm-cm @25°C)1.0E14
Coefficient of Thermal Expansion (1 x 10^-6/°C)8.2
Thermal Conductivity (W/m K)31
Specific Heat (J/kg*K)880
Maximum Working Temperature (°C)1700
Shock Resistance (°C Differential)200
*Note: Properties vary by manufacturer. The above information should be used for general reference purposes only.

related Materials

  • Sapphire – 100% purity Aluminum Oxide with crystalline structure
  • Macor – Easily machinable ceramic with similar electrical resistivity
  • Aluminum Nitride – Softer ceramic with good thermal insulation and electrical resistivity