Abstract
The precipitation hardening effect and a detailed precipitation sequence for the Al–Zn–Mg–Cu (7A85) alloy during its artificial aging at 434 K were investigated by transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) and microhardness testing. The precipitation sequence can be described as: supersaturated solid solution (SSSS) → vacancy-rich clusters (VRC) → Guinier-Preston (GP-Ⅱ) zones → intermediate structures → η′ → η. We found that due to the influence of solute segregation, the evolution of grain boundary precipitates preceeds the formation of intragranular precipitates. The results show that the precipitation hardening of 7A85 aluminum alloy is mainly caused by a series of precipitates between GP-Ⅱ and η′ precipitates.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
