亚共晶Al-Si合金中微量元素La变质共晶Si的关键影响因素

亚共晶Al-Si合金中微量元素La变质共晶Si的关键影响因素

张丽丽, 吉宗威, 赵九洲, 何杰, 江鸿翔

Key Factors Influencing Eutectic Si Modification in Al-Si Hypoeutectic Alloy by Trace La

ZHANG Lili, JI Zongwei, ZHAO Jiuzhou, HE Jie, JIANG Hongxiang

图1 α-Al晶粒周围溶质M (La或Si)浓度分布示意图

Fig.1 Solute M (La or Si) concentration profile around an α-Al grain ( $x_{M}^{0}$ is the initial concentration of solute M; k_M and $x_{M}^{E}$ are the equilibrium partition coefficient and eutectic composition in Al-M binary system, respectively; $S_{M}^{α - A l}$ is the maximum solubility of M in the α-Al phase; $x_{M}^{* L}$ and ${\bar{x}}_{M}^{α - A l}$ are the concentration of solute M in the melt and in the α-Al at α-Al/melt interface, respectively; $x_{M}^{L}$ (T₁) and $x_{M}^{L}$ (T₂) are the solute M concentration in the melt ahead of α-Al/melt interface at temperatures T₁ and T₂, respectively; m is stoichiometric ratio)