Open AccessStudy on thermodynamics basic and alloy phase evolution of Mg-Sn-Si magnesium alloy
Author(s) -
张建新,
王海燕,
高爱华,
樊世克
Publication year - 2015
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.64.066401
Subject(s) - alloy , materials science , atmospheric temperature range , thermodynamics , phase (matter) , precipitation , non equilibrium thermodynamics , thermal expansion , condensed matter physics , analytical chemistry (journal) , metallurgy , physics , chemistry , chromatography , quantum mechanics , meteorology
Thermodynamics basic and alloy phase evolution of Mg-Sn-Si alloy are studied. The results indicate that for Mg-Sn-Si alloy, the specific heat of alloy phase increases with temperature, and it changes quickly at low temperature while gently at high temperature. In the range of low temperature, its thermal expansion increases exponentially with the increase of temperature, and in the range of high temperature the thermal expansion increases linearly. In the two structures of Mg2 (Six, Sn1-x) and Mg2 (Snx,Si1-x) phases, the replacement position of Si or Sn is indefinite, they could be face-center location or vertex location. Under the conditions of conventional solidification, the range of values for x is fluctuant, for it is in nonequilibrium state: x values are around 0.25 and 0.75 for Mg2(Six, Sn1-x) and Mg2(Snx, Si1-x) structure, respectively. The generation temperature of Mg2 (Si, Sn) phase is quite high, it can be precipitated directly from liquid phase, or be transformed from Mg2Si. The generation temperature of Mg2(Sn, Si) phase is lower than that of Mg2(Si, Sn), and it can be precipitated only from the matrix, the initial precipitation temperature of Mg2(Sn, Si) tends to rise with Sn content increasing.