For sintered Neodymium magnets, Aluminum is an ideal surface treatment solution to the from the perspective of anti-corrosion and mechanical strength. The potential difference between Aluminum and Neodymium magnet substrate is quite low which will help magnet avoid electrochemical corrosion. Aluminum coating will obtain a homogenous, dense, and corrosion resistant layer under the atmospheric environments. It should be pointed out that the corrosion products of aluminum coating are non-toxic. In the meanwhile, the corrosion resistance, color, and abrasion of Aluminum coating can be further improved by the subsequently anodizing or electrolytic coloring. Aluminum plating process of sintered Neodymium magnets is mainly utilizing ion vapor deposition (IVD) technology which developed by McDonnell Douglas Corporation for United States Air Force. The initial intention of Aluminum coating is to replace historically Cadmium coating in aerospace and commercial market. Thus Aluminum coated magnets are also manufactured and served for many advanced applications.
Advantages of Aluminum Coated Magnets
- Aluminum coated magnets have superior thickness uniformity.
- Noticeably high temperature resistance.
- Free of hydrogen embrittle phenomenon during the surface treatment process.
- Excellent anti-corrosion capability.
- Outstanding adhesive endurance.
- Very low outgassing, then functions well in vacuum applications.
Characteristics of Aluminum Coated Magnets
- Appearance: Bright silver.
- Coating thickness: 10-30μm.
- Salt spray testing: more than 100hrs.
- Climate testing: more than 500hrs.
- PCT & HAST: more than 200hrs.
- Operating temperature: less than 400 degrees Celsius.