Ni对CoFe合金相稳定性的影响  

The Effect of Ni on Phase Stability of CoFe Alloy

作　　者：戚梦琳 倪晓东[1] 

机构地区：[1]北京科技大学数理学院,北京

出　　处：《凝聚态物理学进展》2017年第2期33-42,共10页Advances in Condensed Matter Physics

摘　　要：本工作利用第一性原理的热力学计算方法,研究了等摩尔配比的CoFe和CoFeNi合金的有序无序转变。计算结果的朗道理论分析表明:1) CoFe和CoFeNi合金的基态均为B2相结构;2) CoFe合金的高温平衡相为BCC结构,当达到转变温度时,CoFe合金会发生B2到BCC结构的相转变,有序无序转变温度大致在1400 K,摩尔组态熵变为;3) 随着Ni的添加,合金体系的转变温度会降低,CoFeNi合金发生了非平衡转变,其高温平衡相为FCC结构,有序无序转变温度低于750 K,摩尔组态熵变为。计算结果与两种合金的有序无序转变实验结果相吻合。In this work, the order-disorder transition of CoFe and CoFeNi alloys with equimolar proportions are studied by using the first-principle thermodynamic calculation method. The calculated results of Landau’s theoretical analysis show that: 1) the ground states of CoFe and CoFeNi alloys are B2 phase structure;2) the high temperature equilibrium phase of CoFe alloy is BCC, when it rises to transition temperature, the phase transition from B2 to BCC will occur in CoFe alloy, the or-der-disorder transition temperature is about 1400 K, and the molar configuration entropy is;3) And with the addition of Ni, the transition temperature of the alloy system will decrease, a non-equilibrium transformation occurs in CoFeNi alloy, the high temperature equilibrium phase of CoFeNi alloy is FCC, the order-disorder transition temperature is lower than 750 K, and the mo-lar configuration entropy is . The calculated results are in good agreement with the expe-rimental results of the order-disorder transition of the two alloys.

关 键 词：第一性原理 有序无序转变 中间相 原子择优占位 

分 类 号：TG14[一般工业技术—材料科学与工程]