Randomexamination after the coating process
© Fraunhofer FEP
The new combinations of materials which make this possible comprise aluminum alloys, high-strength steel, and fiber reinforced plastics. These heterogeneous materials are joined together mechanically using rivets and glued with adhesives. The rivet elements must be able to withstand very high loads: Vibrations at speeds of more than 100 km/h, aggressive ambient air, high temperatures, and a strong electrochemical potential field due to the very different electrochemical potentials of the incorporated materials.Effective protection of the rivets against corrosion and wear reduces the maintenance effort and lowers the risk of material failure.
The Fraunhofer Institute for Electron Beam and Plasma Technology FEP has developed a deposition process for efficiently coating bulk rivets with corrosion protection layers. In a slowly rotating drum the rivets are continually and gently mixed and simultaneously coated in the metal vapor. In a pilot plant up to 30 kg rivets can be coated with a multilayer coating stack using plasma enhanced high-rate deposition and pulse magnetron sputtering. By applying the two vacuum technologies a layer system of alternating aluminum layers of about 1 µm thickness and much thinner sputtered diffusion barrier layers can be achieved. Standard test procedures such as the VDA corrosion test (VDA 621-415) demonstrated the excellent corrosion resistance of the coated rivets. Vacuum coating has two major advantages over the galvanic coating methods used until now: Firstly, it is eco-friendly with regard to the materials used. Secondly, hydrogen embrittlement, which can cause fatigue in high-strength steel and titanium substrates, does not occur in vacuum coating processes.
Dr. Heidrun Klostermann, head of the business unit „Coating of components“ at Fraunhofer FEP, describes further potential applications for the process: „Besides rivets, other small mass-produced components such as screws / bolts, pins, balls, links, or nails of size between 0.2 and 4 cm can be coated as bulk products. By combining different vacuum processes a broad range of materials can be deposited. Hence, the technology is ready for plenty of other coating tasks for bulk products.“Fraunhofer FEP will present samples coated with the described process at PSE 2012 (13th International Conference on Plasma Surface Engineering) in Garmisch-Partenkirchen from 10-14 September 2012. For further information please visit us at our booth or go to our website:
Annett Arnold | Fraunhofer-Institut
Scientists predict a new superhard material with unique properties
18.06.2018 | Moscow Institute of Physics and Technology
A sprinkle of platinum nanoparticles onto graphene makes brain probes more sensitive
15.06.2018 | University of California - San Diego
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...
Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.
From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
18.06.2018 | Earth Sciences
18.06.2018 | Process Engineering
18.06.2018 | Life Sciences