Effect of Strontium Addition on Dendrite Growth and Phase Precipitation in AZ91D Magnesium Alloy
ZHOU Jixue; WANG Bin; TONG Wenhui; YANG Yuansheng
Institute of Metal Research; Chinese Academy of Sciences
Cite this article:
ZHOU Jixue; WANG Bin; TONG Wenhui; YANG Yuansheng. Effect of Strontium Addition on Dendrite Growth and Phase Precipitation in AZ91D Magnesium Alloy. Acta Metall Sin, 2007, 43(11): 1171-1175 .
Abstract Effects of Sr addition on dendrite growth and phase precipitation of AZ91D alloy was studied. The experimental results showed that addition of 0.01-0.1wt%Sr to AZ91D alloy decreased the grain size obviously and promoted formation of globular grains. With the increase of Sr content the morphology of β-Mg17A112 phase in the alloy was changed and the amount of the phase increased. Meanwhile, the needle-like or pole-like Al4Sr phase adhering to the β-Mg17A112 phase at grain boundaries was observed. The enrichment of Sr element at solidification interface front, especially at the tip of α-Mg dendrite, restricts the growth of α-Mg dendrite and changes the preferential growth of α-Mg, which results in the grain refinement and modification of α-Mg dendrite.
[1]Wislei R O,Celia M F,Amauri G.Mater Sci Eng,2005; A402:22 [2]Wang Y X,Guan S K,Wang J Q.Chin J Nonferrous Met, 2003;13:616 (王迎新，关绍康，王建强．中国有色金属学报，2003；13：616) [3]Bamberger M.Mater Sci Technol,2001;17:15 [4]Lee Y C,Dahle A K,Stjohn D H.Metall Mater Trans, 1999;31A:2895 [5]Flemings M C.Metall Trans,1991;22A:957 [6]Vires C.Met Trans,1992;23B:189 [7]Kumar N V R,Blandin J J,Desrayaud C,Montheillet F, Su(?)ry M.Mater Sci Eng,2003;A359:150 [8]Govind,Nair K S,Mittal M C,Lal K,Mahanti R K, Sivaramakrishnan C S.Mater Sci Eng,2001;304-306A: 520 [9]Cai J,Ma G C,Liu Z,Zhang H F,Hu Z Q.J Alloys Compd,2006;422:92 [10]St John D H,Ma Q,Easton M A,Cao P,Hildebrand Z. Metall Mater Trans,2005;36A:1669 [11]Nussbaum G,Bridot P,Warner T J,Charbonnier J, Regazzoni G.In:Mordike B L,Hehmam F.eds.,Mag- nesium Alloys and Their Applications,Oberursel:DMG Informationsgesellschaft,1992:351 [12]Gruzleski J E,Aliravci C A.U S Pat,No.5143564,1992 [13]Makoto T,Suzuki T,Fukui I.J Jpn Inst Light Met,1979; 29:437 [14]Sasaki H,Adachi M,Sato S.J Jpn Inst Light Met,1997; 47:133 [15]Haitani T,Tamura Y,Yano E.J Jpn Inst Light Met,2001; 51:403 [16]Massalski T B,Okamoto H,Subramanian P R,Kaeprzak L.Binary Alloy Phase Diagrams.2nd ed,Metals Park, OH:ASM International,1990:170
