Al_3Li(δ′相)形核机制的计算机模拟研究  

Computer Simulation of Nucleation Mechanism of δ′Phase of Al-Li Alloy

作　　者：李晓玲[1] 刘兵[1] 陈铮[1] 刘晓光[1] 

机构地区：[1]西北工业大学,陕西西安710072

出　　处：《稀有金属材料与工程》2002年第2期110-114,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金资助项目 (5 98710 39)

摘　　要：利用微观 L angevin方程对不同浓度的铝锂合金中的δ′(Al3L i)相的形核过程进行计算机模拟。研究结果表明 :对于锂含量为 15 % (原子百分比 )的合金 ,无序固溶体首先进行协调有序化 ,形成被反相畴界分割的单相有序畴 ;尔后该有序相进行匀相失稳分解 ,贫锂区自发无序化 ,最终形成平衡两相状态。对于锂含量为 12 %的合金 ,Al3L i (δ′相 )通过经典形核机制生成 ,且存在部分小颗粒溶解和粒子间“融合”的现象。由模拟结果还可看出 :时效早期 ,两合金的相界由敏锐变得平滑 ,体系总界面能降低 ,说明形核、长大、粗化等作为伴随过程发生 。The nucleation mechanism of Al 3Li( δ′ phase) in Al Li alloy has been simulated using microscopic Langevin equation It is found that for Al Li alloy containing 15% (atomic fraction) Li, the disordered solution is congruently ordered firstly, resulting in single ordered domains seperated by antiphase domain boundaries, then evolves to equilibrium state by the isostructural decomposition of ordered phase and the spontaneous of disorder Li lean regions For the Al Li alloy containing 12at% Li, the δ′ phase can be formed through interconnection of some particles and dwindling of some smaller particles with the classical nucleation growth mechanism At very early stage of phase transformation for the both alloys,the interfaces between matrix and δ′ phase become smooth and the total interface energies decrease, indicating that the nucleation, growth and coarsening occure in the concomitant processes indeed

关 键 词：微观Langevin方程 Al3Li 形核 计算机模拟 铝锂合金 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TP391.9[金属学及工艺—金属材料]