Electrochemical corrosion of Al-Pd alloys in HCl and NaOH solutions
The corrosion performance of as-solidified Al-Pd alloys in HCl and NaOH aqueous solutions is investigated in this work. Four different alloys (Al88Pd12, Al77Pd23, Al72Pd28 and Al67Pd33, element concentrations are given in at.%) were prepared from high purity Al and Pd lumps by arc-melting i...
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| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
University of Belgrade, Technical Faculty, Bor
2017-01-01
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| Series: | Journal of Mining and Metallurgy. Section B: Metallurgy |
| Subjects: | |
| Online Access: | http://www.doiserbia.nb.rs/img/doi/1450-5339/2017/1450-53391700015P.pdf |
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| Summary: | The corrosion performance of as-solidified Al-Pd alloys in HCl and NaOH
aqueous solutions is investigated in this work. Four different alloys
(Al88Pd12, Al77Pd23, Al72Pd28 and Al67Pd33, element concentrations are given
in at.%) were prepared from high purity Al and Pd lumps by arc-melting in Ar.
Subsequently, the alloy microstructure and phase occurrence were investigated
by a combination of scanning electron microscopy and room-temperature powder
X-ray diffraction. The assolidified Al-Pd alloys were found to consist of
several single-phase microstructure constituents with various structures and
chemical compositions, including structurally complex intermetallic phases.
The polished surfaces of the Al-Pd alloys were subjected to electrochemical
polarization in aqueous HCl and NaOH solutions (0.01 mol.dm-3) at 21±2°C. The
corrosion experiments were conducted in a standard 3-electrode cell
controlled by potentiostat. The corrosion potentials and corrosion current
densities were determined by Tafel extrapolation of the experimental
polarization curves. Phase dissolution has been observed on the alloy
surfaces and some of the phases were preferentially corroded. The effects of
the alloy microstructure and the phase occurrence are evaluated. The local
nobility of individual intermetallic compounds is discussed. Finally, the
conclusions for the alloys corrosion performance in acidic and basic
solutions are provided. |
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| ISSN: | 1450-5339 2217-7175 |