Characterization of localized corrosion of heat treated Er‐ and Zr‐containing A356 alloys in 3.5 wt% NaCl aqueous solution. Issue 2 (24th August 2018) - Colombo, Marco
Abstract : The influences of Er and Zr additions on the corrosion behavior of A356 (Al‐7Si‐0.4Mg) alloy are investigated. Electrochemical tests (potentiodynamic polarization and electrochemical impedance spectroscopy), gravimetric analyses, and microstructural investigations demonstrate that 0.3 wt% Er nominal addition is beneficial for the corrosion resistance of A356 alloy, due to a modified eutectic morphology and a low volume fraction of intermetallic compounds. The further addition of about 0.5 wt% Zr, on the other hand, partially reduces the corrosion resistance of Er‐containing A356 alloy, possibly due to a higher amount of intermetallic compounds which promote corrosion localization. Abstract : The influences of Er and Zr additions on the corrosion behavior of A356 (Al‐7Si‐0.4Mg) alloy are investigated. Electrochemical tests, gravimetric analyses, and microstructural investigations demonstrate that 0.3 wt% Er nominal addition is beneficial for the corrosion resistance of A356 alloy, due to a modified eutectic morphology and a low volume fraction of intermetallic compounds.