Hard anodizing - higher electrolyte temperatures will save energy

The energy consumption of hardanodizing processes is very high. Around 70% of the energy is converted into heat due to Joule heating. To obtain the excellent layer properties, the process must be strongly cooled - usually around 0°C. Research at the Fraunhofer Institute for Manufacturing Engineering and Automation IPA, based on a self designed measuring device, shows that at higher electrolyte temperatures the same properties still can be reached. As an example the common EN AW-6081 alloy was used. The measuring device analyzes the temperatur development at the interface between coating and aluminium. With this device it is possible to find suitable electrolyte temperaturs to safe energy while the coating properties are still excellent. The lectur shows correlations between temperature development and the coating properties and gives an insight how to improve the hardanodizing process for different aluminium alloys in order to safe energy.