Gd-Ni二元相图计算

来源期刊：中南大学学报(自然科学版)1997年第4期

论文作者：夏长清 金展鹏

文章页码：363 - 365

关键词：次规则溶液模型； 热力学参数； 相图计算

Key words：subregular solution model； thermodynamic parameters； calculation of phase diagram

摘    要：采用CALPHAD技术优化计算了Gd－Ni二元相图．液相用Redlich－Kister多项式次规则溶液模型描述，端际固溶体β－Gd，α－Gd，α－Ni分别处理为纯组元bccGd，hcpGd，fccNi．采用热力学评估了如下9个定比化合物：Gd₃Ni(1006．39K，包晶分解)，Gd₃Ni₂(941．07K，包晶分解)，GdNi(1553．15K，同成分熔化)，GdNi₂(1280．10K，包晶分解)，GdNi₃(137．99K，包晶分解)，Gd₂Ni₇(1474．28K，包晶分解)，GdNi₄(1544．44K，包晶分解)，GdNi₅(1753．15K，同成分熔化)和Gd₂Ni₁₇(1553．82K，包晶分解)；热力学计算了3个共晶反应：Gd₃Ni－Gd₃Ni₂(904．97K，31．53%Ni，原子分数，下同)，GdNi－GdNi₂(1232．60K，57．06%Ni)和Gd₂Ni₁₇－Ni(1521．08K，96．24%Ni)．计算结果与相图大部分实验结果在实验误差范围内相吻合．

Abstract: Optimization and calculation of the phase diagram of Gd-Ni binary system have been conducted by using CALPHAD technique. Subregular solution model was used to describe liquid. The terminal solid solution phases, i. e. β-Gd, α-Gd and α-Ni, were treated as pure elements bee Gd, hcp Gd and fcc Ni respectively. The following nine intermetallic compounds were evaluated as line compounds: Gd₃Ni (decomposes at 1006. 39 K), Gd₃Ni₂ (decomposes at 941. 07 K), GdNi (M P 1553. 15 K),GdNi₂ (decomposes at 1280. 10 K). GdNi₃(decomposes at 1372. 99 K), Gd₂Ni₇ (decomposes at 1474. 28 K), GdNi₄(decomposes at 1544. 44 K ), GdNi₅ (M P 1753. 15 K) and Gd₂Ni₁₇ (decomposes at 1553. 82 K). Three eutectic reactions were calculated: Gd₃Ni-Gd3Ni₂(904. 97 K, 31. 53% mole fraction of Ni), GdNi-GdNi₂ (1232. 60 K, 57. 06% mole fracfion of Ni) and Gd₂Ni₁₇-Ni (1521. 08 K, 96. 24% mole fraction of Ni). Both calculated phase diagram and thermodynamic properties agree well with those of most relative experimental data.