Open AccessTheoretical study of ignition-proof mechanism of RE element in Mg alloys
Author(s) -
Guili Liu
Publication year - 2008
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.57.434
Subject(s) - materials science , alloy , embedding , surface energy , energy (signal processing) , cluster (spacecraft) , chemical engineering , analytical chemistry (journal) , chemistry , physics , organic chemistry , composite material , computer science , engineering , quantum mechanics , artificial intelligence , programming language
The atomic cluster models of α-Mg, liquid Mg and the interface between liquid/solid have been founded by computer program. The environment-sensitive embedding energy of RE elements in α-Mg, liquid Mg, liquid/solid interface has been calculated by recursion method. The atomic affinity energy between Mg, La, Y with O has been defined and calculated. The calculated results show that the solid solubility of La and Y is very small in α-Mg, because their higher environment-sensitive embedding energy leads to instability in α-Mg crystal. The RE elements diffuse to the liquid Mg, which has lower environment-sensitive embedding energy than the solid, and congregate on the surface of liquid Mg as the alloy solidifies. Because the atomic affinity energy of RE-O is lower than Mg-O(The atomic affinity energy between Mg, La, Y with O are Mg-O-14.9338eVLa-O-19.0608 eVY-O-19.5050 eV, respectively), the RE elements congregating on the surface of liquid Mg will priorily combined with O, forming compact RE oxides, which prevent Mg alloys from burning.