The irregular structure of an Al-Si eutectic has been chemically modified by adding small amount of Sr (300 ppm). The initially coarse flake structure was converted into technologically preferable fine fibrous morphology. The selective phase dissolution has been investigated using two different electrochemical approaches, derived from superimposed Pourbaix diagrams. Anodisation at 0.3 V (SHE) in 1 M HCl led to pitting and was partially successful after an extended period of time (20 h). Electropolishing in a mixture of perchloric acid and methanol (10:90) at 0 °C proved successful in both the partial and the complete matrix dissolution, without affecting silicon structures.
Sprache der Kurzfassung:
Englisch
Englischer Titel:
Selective matrix dissolution in an Al–Si eutectic
Englische Kurzfassung:
The irregular structure of an Al–Si eutectic has been chemically modified by adding small amount of Sr (300 ppm). The initially coarse flake structure was converted into technologically preferable fine fibrous morphology. The selective phase dissolution has been investigated using two different electrochemical approaches, derived from superimposed Pourbaix diagrams. Anodisation at 0.3 V (SHE) in 1 M HCl led to pitting and was partially successful after an extended period of time (20 h). Electropolishing in a mixture of perchloric acid and methanol (10:90) at 0 °C proved successful in both the partial and the complete matrix dissolution, without affecting silicon structures.
Journal:
Corrosion Science
Volume:
51
Seitenreferenz:
1490-1495
Erscheinungsjahr:
2009
ISSN:
1879-0496
Anzahl der Seiten:
6
Notiz zur Publikation:
Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, 40237 Düsseldorf, Germany / Srdjan Milenkovic, Vincent Dalbert, Ratko Marinkovic, Achim Walter Hassel
Forschungs-