Cavitation behavior of fine grained AZ31 alloy sheet during hot blow forming

✍ Scribed by Yong-Nam Kwon; Sang-Hyun Kim; Young Seon Lee

• Publisher: Elsevier
• Year: 2011
• Tongue: English
• Weight: 712 KB
• Volume: 10
• Category: Article
• ISSN: 1877-7058
• DOI: 10.1016/j.proeng.2011.04.572

✦ Synopsis

Cavitation behaviors of fine grained AZ31 alloy sheet during high temperature blow forming have been investigated in terms of deformation and microstructure evolution. Especially, effect of hydrostatic stress by applying backward pressure on blow formability has been investigated by examining cavitation behavior. A commercial grade AZ31 magnesium alloy sheet with the grain size of 15m could have an elongation over 300% over 400C. However, elongation did not show a strong strain rate and temperature dependencies which could be easily found in most superplastic aluminum alloys. It might result from that AZ31 would be vulnerable to cavitation even at the early stage of deformation. It was also found that hydrostatic stress was not effective to prevent evolution of cavities during blow forming, which was much different with the case in most superplastic alloys. Both low strain rate dependency of elongation and ineffectiveness of hydrostatic stress might be originated from poor accommodation slip for grain boundary sliding of AZ31 even at high temperature where non basal slip systems were activated.