2013 Award Winners
Award-winning project: Innovative method reduces testing time for zinc flake systems
Project partners: Daimler AG | Holder GmbH Oberflächentechnik | Ingenieurbüro Peter Schrems (IPS) | Steinbeis-Transferzentrum Korrosion und Korrosionsschutz (Friedrichshafen)
Zinc flake coatings are used to protect metal components in the automotive industry against corrosion. To ensure the quality of the coatings, time-consuming corrosion tests lasting up to three months are required in series production. This means that changes to the coatings and any necessary corrective measures are only identified after a corresponding delay. The Steinbeis Transfer Centre for Corrosion and Corrosion Protection, based in Friedrichshafen and at Ravensburg-Weingarten University of Applied Sciences, has therefore developed – in collaboration with Daimler AG, Holder GmbH Oberflächentechnik and the engineering firm Peter Schrems (IPS) – an innovative test method that will enable zinc flake coatings to be assessed for their corrosion protection effectiveness many times faster in future.
In this short-term test procedure, an electrical voltage is applied to the component under investigation in an electrochemical measuring cell, simulating the corrosion stresses encountered during operation. The course of the measurement signal is specific to the quality of the coating and can, where necessary, be supplemented by other analytical evaluation methods. Thanks to the use of a stand-alone potentiostat newly developed by IPS and the Steinbeis team – in which software automatically evaluates the measurement results – scientifically trained personnel are no longer required to interpret the measurement results. The success of the method was demonstrated under laboratory conditions in collaboration with the coating specialist Holder GmbH Oberflächentechnik and Daimler AG for a zinc lamellar coating applied in series production. Reliable and reproducible results are now available after just four hours of testing. This makes it possible to react much more quickly to changes in quality and to initiate the necessary corrective measures. By increasing the frequency of measurements, processes can be run within a tighter process window, whilst at the same time reducing the costs associated with time-consuming in-production testing.
A further challenge currently lies in implementing the method into the ongoing production process using a measuring cell that can be applied directly to the component. The method, which was awarded the Steinbeis Foundation’s Transfer Prize – the Löhn Prize, holds enormous potential, following appropriate modification, for use in the quality management of other coating processes and surface technologies.