Investigation of time-dependent corrosion behavior of Sr-modified AlSi12 alloy

Duygun I. K., HAPÇI AĞAOĞLU G., ORHAN G.

INTERNATIONAL JOURNAL OF MATERIALS RESEARCH, vol.111, no.4, pp.339-346, 2020 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 111 Issue: 4
  • Publication Date: 2020
  • Doi Number: 10.3139/146.111882
  • Journal Name: INTERNATIONAL JOURNAL OF MATERIALS RESEARCH
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, PASCAL, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.339-346
  • Istanbul University Affiliated: No

Abstract

The effect of Sr addition on the microstructure and time-dependent corrosion properties of the AlSi12 eutectic alloy was investigated. The modified alloy contained 90 +/- 3 ppm Sr. The microstructural differences in the eutectic structure of AlSi12 alloys were assessed in terms of the Si particle size and alpha-Al volume fraction. The unmodified and Sr-modified alloys were immersed for 1, 24, 72 and 120 h in 3.5 wt.% NaCl. Electrochemical impedance spectroscopy and potentiodynamic polarization techniques were performed to analyze the corrosion characteristics of the alloys. Sr addition led to a decrease in the Si particle size, and the formation of long dendritic alpha-Al. It was found that the presence of Sr resulted in more stable corrosion behavior up to 24 h. The deterioration of the corrosion behavior of Sr-modified alloy was observed with the further increase of immersion time.