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Lecture

Investigations on the structure of PEO layers

Thursday (09.11.2017)
15:00 - 15:20
Part of:


A. E. R. Friedemann1 2 3, K. Thiel1, Th. M. Gesing2 3, P. Plagemann1


1FRAUNHOFER Institut für Fertigungstechnik Angewandte Materialforschung IFAM, Wiener Straße 12, D-28359 Bremen, Germany

2Institut für Anorganische Chemie und Kristallographie, Leobener Straße /NW2, Bibliothekstraße 1, Universität Bremen,

D-28359 Bremen, Germany

3MAPEX Center for Materials and Processes, Bibliothekstraße 1, Universität Bremen, D-28359 Bremen, Germany


The Plasma electrolytic oxidation (PEO) is a type of high-voltage anodic oxidation capable to produce a thick oxide layer with a wide range of coating structures influenced by the electrolytic system. This process enables the combined adjustment of both characteristics, i.e. the morphology and chemical composition. Thus, the possibility exists to generate an individual structure and to form a crystalline surface in a single step respectively [1, 2]. A highly porous surface with a high crystalline content is ensured through the process of plasma electrolytic oxidation of pure titanium. In the present study the plasma electrolytic oxidized TiO2-layer were investigated about its crystallinity through the layer thickness. The layers were prepared with a high applied voltage to optimize the crystallinity of the PEO layer. Raman spectroscopy and electron backscattering diffractometry (EBSD) were selected to clarify the structure of the oxide layer in its crystallinity and phase composition. The composition of the TiO2-phases is more or less irregular distributed resulting from the higher energy input on the uppermost side of the layer. Scanning transmission electron microscopy (STEM) should provide a deeper understanding of the structure and the effects of plasma discharges on the layer. Therefore it is an indication that the plasma discharges have a strong influence on crystallite formation on top of the oxide layer.


[1] R.C. Petersen, Titanium Implant Osseointegration Problems with Alternate Solutions Using Epoxy/Carbon-Fiber-Reinforced Composite, Metals (Basel). 4 (2014) 549–569. doi:10.3390/met4040549.

[2] S. Stojadinovi?, R. Vasili?, M. Petkovi?, B. Kasalica, I. Bel?a, A. Žeki?, L. Zekovi?, Characterization of the plasma electrolytic oxidation of titanium in sodium metasilicate, Appl. Surf. Sci. 265 (2013) 226–233. doi:10.1016/j.apsusc.2012.10.183.


 

Speaker:
Ariane Friedemann
Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM
Additional Authors:
  • Dr. Peter Plagemann
    Fraunhofer IFAM
  • Prof. Dr. Thorsten M. Gesing
    Universität Bremen