A green coloured, heat-cured finish from Vacuumschmelze protects VAC permanent rare earth magnets in extreme conditions of up to 250°C. The VacCoat 30033 adhesive coating and corrosion protection finish can be used at temperatures up to 200°C in continuous operation and can withstand peak temperatures of up to 250°C for periods of several hours. The spray coating also provides corrosion protection and is, according to the company, particularly suitable for salt-water environments and automotive engine and motor applications. It has corrosion inhibiting additives to the basic formula of the company's earlier coating. The epoxy coating offers protection that survives between two and three times longer in relevant corrosion tests, and is also stronger, claims the company. When a coating was applied to NdFeB magnets at the standard thickness of around 20µm, the material showed corrosion resistance periods of over 1000hrs in typical accelerated corrosion tests for permanent magnets. This level of durability, even in salt-water environments, allows it to be used for magnets in offshore wind turbines and tidal power stations. In automotive applications, which frequently require a combination of corrosion resistance to EN ISO 9227 salt spray testing and moisture resistance, the coating can extend the life of magnets used in engines and motors.
