Time-dependent corrosion properties of Sr-modified AlSi9 alloy analyzed by electrochemical techniques


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

JOURNAL OF ALLOYS AND COMPOUNDS, cilt.803, ss.786-794, 2019 (SCI İndekslerine Giren Dergi)

  • Cilt numarası: 803
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1016/j.jallcom.2019.06.330
  • Dergi Adı: JOURNAL OF ALLOYS AND COMPOUNDS
  • Sayfa Sayısı: ss.786-794

Özet

The relation between time-dependent corrosion behaviors and microstructural characteristics of Sr modified and unmodified AlSi9 alloy was studied. The melted alloys were cast into the permanent mold at 700 degrees C casting temperature. The Effect of holding time in the furnace on chemical compositions of alloys was determined. Sr content of the modified alloys was 200 +/- 5 ppm after 4 h and 50 +/- 2 ppm after 17 h holding time. Microstructural properties were analyzed after casting. The corrosion behavior of AlSi9 depending on Sr content was investigated by means of electrochemical impedance spectroscopy technique and potentiodynamic polarization plots in 3.5 wt% NaCl solution at 25 degrees C. The effect of immersion time was examined at 1, 24, 72 and 120 h. The results indicated that high Sr content in AlSi9 alloy contributes to the formation of a finer eutectic phase and more stable corrosion behavior during immersion time. (C) 2019 Elsevier B.V. All rights reserved.