Journal Article

·2017 OPEN ACCESS

Effect of Sr and Ti Addition on the Corrosion Behaviour of Al-7Si-0.3Mg Alloy

Muhammet Uludağ , Mustafa Kocabaş YTU , Derya Dışpınar , Remzi Çetin , Nurhan Cansever YTU

Archives of Foundry Engineering

Abstract

Abstract In the present study, the corrosion behaviour of A356 (Al-7Si-0.3Mg) alloy in 3.5% NaCl solution has been evaluated using cyclic/potentiodynamic polarization tests. The alloy was provided in the unmodified form and it was then modified with AlTi5B1 for grain refinement and with AlSr15 for Si modifications. These modifications yield to better mechanical properties. Tensile tests were performed. In addition, bifilm index and SDAS values were calculated and microstructure of the samples was investigated. As a result of the corrosion test, the Ecorr values for all conditions were determined approximately equal, and the samples were pitted rapidly. The degassing of the melt decreased the bifilm index (i.e. higher melt quality) and thereby the corrosion resistance was increased. The lowest corrosion rate was founded at degassing and as-received condition (3.9x10 -3 mm/year). However, additive elements do not show the effect which degassing process shows.

Keywords

Materials science Corrosion Alloy Microstructure Ultimate tensile strength Metallurgy Polarization (electrochemistry) Grain size

Subject Areas

Aluminum Alloy Microstructure Properties ·Aerospace Engineering ·Physical Sciences
Aluminum Alloys Composites Properties ·Mechanical Engineering ·Physical Sciences
Microstructure and mechanical properties ·Materials Chemistry ·Physical Sciences

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