摘要
采用三元微观相场动力学模型,模拟研究了973,1173,1253K时效温度下,Ni75Al15Fe10合金中γ′相的早期沉淀过程。通过对该合金原子显微形貌,长程序参数和浓度及Fe原子在不同格点占位分数随时间演化的模拟计算分析得出:随着温度的升高,Ni75Al15Fe10合金的沉淀机制由等成分有序化兼失稳分解机制向非经典形核长大机制过渡;γ′相沉淀析出的孕育期变长;Fe原子在B格点的占位越来越困难,占位几率降低;合金沉淀析出的γ′相为单一L12结构的Ni3(AlFe)复合相。
A ternary microscopic phase-field kinetic model was used to investigate the early γ＇ precipitation process of Ni75Al15Fe10 alloy by simulating the evolution of the atomic morphology, calculating long-range order parameters and concentration, and characterizing the curve of site occupation of Fe atoms at different lattice sites in the γ＇ phase at annealed temperatures 973, 1173, 1253 K. The results show, while the temperature increasing, γ＇ precipitation mechanism of Ni75Al15Fe10 alloy is transformed from the congruent ordering and spinodal decomposition to non-classic nucleation and growth; the incubation period of the γ＇ phase is prolonged; Fe atoms more and more difficultly occupy the B-site （the corner site of fee） and the occupation probability gradually decreases. The precipitated ）,＇ phase （Ll2 structure） is a kind of the complex Ni3（Al1-xFex） single-phase
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2007年第10期1797-1801,共5页
Rare Metal Materials and Engineering
基金
国家自然科学基金资助(50071084)
国家"863"项目(2002AA331051)
西北工业大学研究生创业种子基金(Z200714)
关键词
时效温度
微观相场方程
沉淀
替代
γ’相
ageing temperature
microscopic phase-field equation
precipitation
substitute
γ＇ phase
