ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Microstructural, morphological characterization and corrosion behavior of sand cast AlSi10Cu(Fe) alloy in chloride solution

Belkacem Korichi, Nacer Zazi, Stéphanie Delbrel, Kieu Ngo, and Jean Paul Chopart

Laboratoire de Mécanique, Structures et Energétique, Université Mouloud Mammeri de Tizi-Ouzou, Tizi-Ouzou, Algeria

E-mail: zazinacer@yahoo.fr

Received: 17 October 2021  Accepted: 3 January 2022

Abstract:

In order to examine the relationship between the microstructure and the corrosion behavior in chloride solution, the microstructure of AlSi10Cu (Fe) sand cast aluminum alloy has been investigated by using different techniques including scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction analysis and electrochemical measurements. The microscopic analysis and X-ray diffraction analysis show several phases in addition to matrix phase, including pores and phases at nano- and microscales. The average rate of micropores and nanopores is 4% and 5%, respectively. The nanoparticle size varies between 20 and 150 nm. Plates and corals-like silicon eutectic, rich-Cu phase and Chinese script phase (Al₁₅(Mn,Fe)₃Si₂) have been observed. Energy-dispersive spectroscopy analyses show the presence of a new phase (Cu_61.22 Zn_25.39Ni_11.85 Al_1.54), and the pitting corrosion has been demonstrated to be initiated at the nanopores. The electrochemical measurements exhibited the effect of several elements and porosities on the corrosion kinetics that is controlled by charge transfer and diffusion phenomenon. Wide passive windows, followed by the breakdown of passive film and excessive dissolution, have been observed in 0.3 and 3 wt% NaCl solutions. The electrochemical measurements show a high corrosion rate which does not recommend the use of this alloy in seawater.

Keywords: AlSi10Cu(Fe) cast alloy; Plates-like silicon eutectic; Corals-like silicon eutectic; Cu61.22 Zn25.39Ni11.85 Al1.54 phases; Aluminum corrosion; Nanopores

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02064-9

Chemical Papers 76 (5) 2947–2967 (2022)