Coarsening of equiaxed microstructure in the semisolid state of aluminum 7075 alloy through SIMA processing

Bolouri, Amir; Shahmiri, Mohammad; Kang, Chung Gil

Abstract

In the present study, the coarsening mechanism of equiaxed grains in the semisolid state of aluminum 7075 alloy, treated via strain induced melting activation process, was investigated. The kinetics of equiaxed grain growth in the semisolid state of the experimental alloy was determined. The results revealed that when the holding temperature increased, the coarsening rate constant (K) showed a precipitously increasing character in the range of 590-610 °C. This was attributed to the extensive effect of the coalescence mechanism on the grain growth at the high solid fractions. By further increasing the holding temperature to 620 and 625 °C (increasing the liquid fraction), the effect of coalescence on the grain growth appeared to be weakened, that is, although there was a slight decrease at 620 °C, a gently increasing character could be generally supposed. Severe segregation of Zn and Cu alloying elements at grain boundaries and intragranular droplets was detected at 620 and 625 °C after 15 and 10 min, respectively. © 2011 Springer Science+Business Media, LLC.

• Journal Article Type: Article
• Acceptance Date: Dec 10, 2011
• Online Publication Date: Dec 28, 2011
• Publication Date: Apr 1, 2012
• Journal: Journal of Materials Science
• Print ISSN: 0022-2461
• Electronic ISSN: 1573-4803
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 47
• Issue: 8
• Pages: 3544-3553
• DOI: https://doi.org/10.1007/s10853-011-6200-6
• Keywords: aluminium 7075 alloy, SIMA processing
• Public URL: https://uwe-repository.worktribe.com/output/951837
• Publisher URL: http://dx.doi.org/10.1007/s10853-011-6200-6