Fraunhofer-Gesellschaft

Publica

Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Surface topography development of cobalt under near-ECM conditions

Entwicklung der Oberflächentopographie von Cobalt unter ECM-nahen Bedingungen
 
: Schneider, M.; Schubert, N.; Michaelis, A.

Zybura-Skrabalak, Maria ; Institute of Advanced Manufacturing Technology, Krakow:
8th International Symposium on Electrochemical Machining Technology, INSECT 2012. Proceedings : Organised in Krakow on 18th - 19th October 2012
Kraków, 2012
ISBN: 978-83-931339-5-6
pp.67-75
International Symposium on Electrochemical Machining Technology (INSECT) <8, 2012, Krakow>
English
Conference Paper
Fraunhofer IKTS ()
anodische Auflösung; Blasenbildung; Cobalt; elektrochemische Bearbeitung; Gasblase; Oberflächentopographie; Stromdichte

Abstract
The authors investigated the anodic dissolution of cobalt in sodium nitrate solution under near-ECM conditions. The main object was the surface topography development at a moderate current density (25A/cm 2) by using a special channel flow cell. The dissolution of cobalt in this current range seems to be in a transition state between heterogeneous and homogeneous dissolution. Oxygen evolution is observable only in the early stage of the experiments.The present work was focused on anodic dissolution of cobalt under near-ECM conditions at a moderate applied current density. By using a special channel flow cell the authors observed the process and the surface topography as well. It could be shown that: the voltage response does not show any hint on a mechanism change from active to transpassi ve dissolution of cobalt, a side reaction associated with gas bubbling (oxygen evolution) only happens in the early state of the pulse experiment, preferred dissolution on defects (grain boundaries), the topography development changes from homogeneous removal during the 1st pulse to heterogeneous removal during the 2nd pulse, post-experiment investigation supports the assumption of a crystallographic orientated topography development during the 2nd pulse.

: http://publica.fraunhofer.de/documents/N-238639.html