Aluminum Oxide (Al2O3) Coatings

At Hannecard-ASB, we provide high-performance aluminum oxide (Al2O3) coatings for a wide range of applications. Also known as alumina coating or "beta ceramic," aluminum oxide protective coatings are a highly durable and chemically stable coating solution. AL2O3 coating creates superior wear resistance, electrical insulation, and chemical stability. It naturally provides a passivation layer on coated substrates that prevents weathering and environmental corrosion. Aluminum oxide coatings are also highly cost-effective, making them an excellent solution for protective coatings across a broad range of industrial sectors.

Benefits of AL203 Coating

• Increases resistance to wear caused by extreme friction and mechanical abrasion
• Resistant to acids, alkalis, and other chemicals
• Acts as a thermal barrier in high-heat environments up to 3,000°F
• Offers 300-400 volts per 0.001-inch thickness at room temperature
• Can provide non-stick properties against various liquids and melted metals

How Are Aluminum Oxide Protective Coatings Applied?

We apply aluminum oxide protective coatings using two primary methods: plasma electric arc coating process with powdered feedstock, or HVOF Powder Combustion with ceramic-based feedstock. [KE1] Using these processes, we can produce alumina coatings in varying thicknesses to meet the unique requirements of your application. Additional methods, such as the introduction of a bond coat material, can be used to produce an additional layer of protection to your aluminum oxide coating to better protect the substrate from corrosion.

Chemistry Options and Properties for AL2O3 Coatings

Aluminum oxide coatings are available in numerous chemistries, each offering unique advantages. Nearly pure Al₂O₃ enhances dielectric properties, making it ideal for electrical insulation. When combined with titanium oxide additives, the coating gains increased wear and corrosion resistance. Aluminum oxide coatings can also be engineered to prevent current transfer and reduce arc erosion, protecting parts in high-voltage or high-friction environments.

At Hannecard-ASB, we customize coatings to meet your exact part performance requirements for your application. Based on your requirements, we can also utilize highly specialized chemistries, including fused and crushed mixtures and cladded oxide.

Properties of Aluminum Oxide Coatings

Low-Temperature LT-Al₂O₃

• Deposition Temperature: ~250 °C
• Hardness: 9-11 GPa
• Thickness: 4-6 µm
• Structure: Amorphous
• Chemical Stability: Not stable in alkaline solutions
• Electrical Properties: Good electrically insulating properties

High-Temperature HT-Al₂O₃

• Deposition Temperature: ~530 °C
• Hardness: 19-21 GPa
• Thickness: 1-3 µm
• Structure: Gamma Al₂O₃
• Chemical Stability: High
• Additional Properties: Good electrically insulating properties and high wear resistance