中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 18 No. 3 June 2008 |
（Department of Materials Engineering, Shenyang Institute of Aeronautical Engineering, Shenyang 110034, China）
Abstract:In order to obtain fine-microstructure magnesium alloys with superior mechanical properties, AZ61 alloy was processed by friction stir processing(FSP) combined with rapid heat sink. It is found that ultrafine-grained microstructure with average size less than 300 nm is observed in the resultant AZ61 alloy. The mean microhardness of the ultra-fine region reaches Hv120−130, two times higher than that of AZ61 substrate. All these results demonstrate clearly that under a cooling rate high enough, ultra-fine structure in AZ61 alloy with superior mechanical properties can be produced by one pass FSP via dynamic recrystallization.
Key words: magnesium based alloys; AZ61 alloy; friction stir processing; ultrafine-grained microstructure
