镍基高温合金中γ″和δ相的热力学性质与相变判定  

Thermodynamic properties and phase transition determination ofγ″andδphases in nickel-based superalloy

作　　者：孙昊昉 田素贵[1] 刘丽荣[1] 金莹 SUN Hao-fang;TIAN Su-gui;LIU Li-rong;JIN Ying(School of Materials Science and Engineering,Shenyang University of Technology,Shenyang 110870,China;School of Energy and Power Engineering,Shenyang University of Chemical Technology,Shenyang 110142,China)

机构地区：[1]沈阳工业大学材料科学与工程学院,沈阳110870 [2]沈阳化工大学能源与动力工程学院,沈阳110142

出　　处：《沈阳工业大学学报》2021年第5期529-536,共8页Journal of Shenyang University of Technology

基　　金：国家自然科学基金重点项目(50634030).

摘　　要：为了判定GH4169合金中具有相同成分但不同结构的γ″相和δ相的相变类型,利用第一性原理模拟和状态方程方法计算了γ″相和δ相的能量体积关系曲线及相关热力学性质,并对其结果进行比较分析.结果表明,在γ″相至δ相的相变过程中化学势保持不变,具有化学势一阶偏导形式的热力学性质不变,但具有二阶偏导形式的热力学性质发生跃变.因此,γ″相至δ相的转变为二级相变,且该相变符合二级相变的空间群关系,遵从理论相变路径.In order to determine the phase transition type ofγ″andδphases with the same composition and different structures in GH4169 superalloy,the first principle simulation and the state equations were used to calculate energy-volume relationship curves and related thermodynamic properties ofγ″andδphases,and relative consequences were compared and analyzed.The results show that during the transition progress fromγ″phase toδphase,the chemical potential is unchanged,the thermodynamic properties with the first-order partial derivative form of chemical potential remain unchanged,but the thermodynamic properties with the second-order partial derivative form exhibit a sudden change.Therefore,the transition progress fromγ″phase toδphase is a second-order phase transition,in accordance with the space group relationship of second-order phase transition,and in consistence with the path of theoretical phase transition.

关 键 词：高温合金 析出相 相变 稳定性 热力学 化学势 空间群 第一性原理 

分 类 号：TG111[金属学及工艺—物理冶金]