Response of Microstructure in High Strength Aluminium Alloy to Graff Sargent Etchant

Abstract:

The response of microstructure in high strength Al-Zn-Mg-Cu aluminum alloy 7055 to Graff Sargent etchant was investigated. It was found that grain boundaries and subgrain boundaries were easily corroded due to presence of η phase, and grain boundaries were corroded more rapidly than subgrain boundaries. The grain structure could be revealed quite clearly after immersion for about 15s. S (Al₂CuMg) and Al₇Cu₂Fe phase were quite stable during immersion if the time was not very long. A dealloying for Al/Mg in the S and Al₇Cu₂Fe phase was found after long time immersion. Prolonged immersion resulted in serious corrosion of subgrain boundaries, consequently separation of fine subgrains.

• Periodical: Materials Science Forum (Volume 877)
• Pages: 508-513
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.877.508
• Online since: November 2016
• Authors: Cheng Bo Li, Shao Lin Wang, Sheng Dan Liu*, Xin Ming Zhang
• Keywords: Grain Boundaries, High Strength Aluminium Alloy, S Phase

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