中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 21 No. 4 April 2011 |
（1. College of Metallurgy and Materials Engineering,
Chongqing University of Science and Technology, Chongqing 401331, China;
2. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
3. National Engineering Research Center for Magnesium Alloy, Chongqing 400044, China）
Abstract:The effects of Sr and Y with different contents on the microstructure and corrosion resistance of AZ31 alloy were investigated. The results indicate that the addition of Sr can obviously reduce the grain size of AZ31 alloy and transform β-Mg17Al12 phase from continuous network to scattered form. Simultaneously, Al4Sr phase distributed along the boundaries of grains is formed in AZ31-Sr magnesium alloys. The addition of Sr is not as effective as the simultaneous addition of Sr+Y for the refinement of grains, and Al2Y and Al3Y phases are distributed both in intracrystalline and along grain boundaries. The corrosion resistance is improved slightly in AZ31 alloy with simultaneous addition of 0.5%Sr+Y. Due to its smallest corrosion current density and corrosion rate, the corrosion resistance of AZ31-0.5%Sr-1.5%Y magnesium alloy is proved the best.
Key words: AZ31 magnesium alloy; strontium; yttrium; corrosion resistance
