(1. 湘潭大學(xué) 材料設(shè)計(jì)及制備技術(shù)湖南省重點(diǎn)實(shí)驗(yàn)室,湘潭 411105;
2. 湘潭大學(xué) 裝備用關(guān)鍵薄膜材料及應(yīng)用湖南省國(guó)防科技重點(diǎn)實(shí)驗(yàn)室,湘潭 411105;
3. 湘潭大學(xué) 材料科學(xué)與工程學(xué)院,湘潭 411105)
摘 要: 采用平衡合金法,利用掃描電鏡和X射線衍射等方法對(duì)Li-Si-Zr三元系的470K等溫截面的相關(guān)系進(jìn)行了實(shí)驗(yàn)測(cè)量。結(jié)果表明:該等溫截面中存在(Si)+ZrSi2+ZrLiSi三相區(qū);采用CALPHAD方法對(duì)Li-Si-Zr三元系進(jìn)行了熱力學(xué)優(yōu)化。首先優(yōu)化計(jì)算了Li-Zr二元系,其中熔體相(Liquid、BCC、FCC和HCP)采用替換溶液模型,過(guò)剩自由能用Redlich-Kister多項(xiàng)式展開(kāi);然后,結(jié)合文獻(xiàn)中已有的Li-Si和Si-Zr體系的熱力學(xué)參數(shù),對(duì)Li-Si-Zr三元系進(jìn)行了熱力學(xué)優(yōu)化。計(jì)算結(jié)果與實(shí)驗(yàn)數(shù)據(jù)符合得較好,獲得了一套較為合理的熱力學(xué)參數(shù)。
關(guān)鍵字: Li-Si-Zr三元系;相平衡;平衡合金法;熱力學(xué)優(yōu)化
(1. Key Laboratory of Materials Design and Preparation Technology of Hunan Province,
Xiangtan University, Xiangtan 411105, China;
2. Hunan Provincial National Defense Key Laboratory of Key Film Materials and Application for Equipment,
Xiangtan University, Xiangtan 411105, China;
3. School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China)
Abstract:The isothermal section of the Li-Si-Zr ternary system at 470 K was studied through equilibrated alloy method by scanning electron microscopy and X-ray diffractometry. The results show that there is (Si)+ZrSi2+ZrLiSi three-phase equilibrium at this isothermal section. Based on the measured data obtained in this work and some information on experimental phase diagram in literature, the thermodynamic assessment of the Li-Si-Zr ternary system was performed with the CALPHAD method. Firstly, the Li-Zr binary system was thermodynamically assessed. The solution phases including liquid, BCC, FCC and HCP were described with a substitutional model, of which the excess Gibbs energies were formulated with the Redlich-Kister polynomial. Then, combined with the thermodynamic parameters of the Li-Si and Si-Zr binary systems cited from literatures, the Li-Si-Zr ternary system was thermodynamically assessed. The calculated results agree well with the experimental data. A set of rational thermodynamic parameters for the ternary system are obtained.
Key words: Li-Si-Zr ternary system; phase equilibrium; equilibrated alloy method; thermodynamic assessment


