Next Article in Journal
On the Modelling of the Transient Flow Behavior of Metallic Glasses: Analogy with Portevin-Le Chatelier Effect
Next Article in Special Issue
Surface and Microstructural Failures of PET-Coated ECCS Plates by Salmon-Polymer Interaction
Previous Article in Journal / Special Issue
Effect of Synthesizing Temperature on Microstructure and Electrochemical Property of the Hydrothermal Conversion Coating on Mg-2Zn-0.5Mn-Ca-Ce Alloy
Article Menu

Export Article

Open AccessArticle
Metals 2016, 6(3), 46; doi:10.3390/met6030046

Al-Co Alloys Prepared by Vacuum Arc Melting: Correlating Microstructure Evolution and Aqueous Corrosion Behavior with Co Content

Department of Materials Science and Engineering, University of Ioannina, Ioannina 45110, Greece
*
Author to whom correspondence should be addressed.
Academic Editors: Vineet V. Joshi and Alan Meier
Received: 18 January 2016 / Revised: 11 February 2016 / Accepted: 19 February 2016 / Published: 27 February 2016
(This article belongs to the Special Issue Oxidation of Metals)
View Full-Text   |   Download PDF [6526 KB, uploaded 27 February 2016]   |  

Abstract

Hypereutectic Al-Co alloys of various Co contents (7–20 weight % (wt.%) Co) were prepared by vacuum arc melting, aiming at investigating the influence of the cobalt content on the microstructure and corrosion behavior. Quite uniform and directional microstructures were attained. The obtained microstructures depended on the Co content, ranging from fully eutectic growth (7 wt.% and 10 wt.% Co) to coarse primary Al9Co2 predominance (20 wt.% Co). Co dissolution in Al far exceeded the negligible equilibrium solubility of Co in Al; however, it was hardly uniform. By increasing the cobalt content, the fraction and coarseness of Al9Co2, the content of Co dissolved in the Al matrix, and the hardness and porosity of the alloy increased. All alloys exhibited similar corrosion behavior in 3.5 wt.% NaCl with high resistance to localized corrosion. Al-7 wt.% Co showed slightly superior corrosion resistance than the other compositions in terms of relatively low corrosion rate, relatively low passivation current density and scarcity of stress corrosion cracking indications. All Al-Co compositions demonstrated substantially higher resistance to localized corrosion than commercially pure Al produced by casting, cold rolling and arc melting. A corrosion mechanism was formulated. Surface films were identified. View Full-Text
Keywords: Al-Co alloys; hypereutectic; Al9Co2; complex metallic alloys; vacuum arc melting; directional growth; aqueous corrosion; reverse polarization; pseudo-passivation; Raman spectroscopy Al-Co alloys; hypereutectic; Al9Co2; complex metallic alloys; vacuum arc melting; directional growth; aqueous corrosion; reverse polarization; pseudo-passivation; Raman spectroscopy
Figures

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Lekatou, A.; Sfikas, A.K.; Petsa, C.; Karantzalis, A.E. Al-Co Alloys Prepared by Vacuum Arc Melting: Correlating Microstructure Evolution and Aqueous Corrosion Behavior with Co Content. Metals 2016, 6, 46.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Metals EISSN 2075-4701 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top