Al-Li合金分级时效的微观相场模拟  

Investigation on Aging-Reaging of Al-Li Alloys Using Computer Simulation

作　　者：徐国栋[1] 陈铮[1] 李永胜[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》2007年第7期1229-1233,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50071046);国家高技术研究发展计划项目(2002AA331051)资助

摘　　要：基于离散格点形式的微观相场动力学扩散方程,以Al-10at%Li合金为对象,对3种不同的时效工艺进行计算模拟。结果表明,对于该合金,采用137℃预时效+190℃终时效工艺比另2种时效工艺获得的组织更均匀,颗粒更细化、弥散度更高。Al-10at%Li合金的单级时效和分级时效的沉淀相δ′(Al3Li)由失稳分解+形核长大的混合方式形成。分级时效可以有效地提高有序相的体积分数和颗粒密度。In this paper, three different aging treatments for Al-10at%Li alloy were investigated using computer simulation based on the microscopic diffusion equations with the discrete format. The results show that the microstructure of the Al-10at%Li alloy aging at 137 ℃ and reaging at 190 ℃ is more homogeneous than the two others in size and distribution. And the nucleation mechanisms of precipitate δ＇（Al3Li） phase were discussed in detail. For the Al-10at%Li alloy, the δ＇ phases are formed by the mixed fashion of nucleation-and-growth mechanism and spinodal decomposition mechanism during the aging and reaging. The aging-reaging can effectively increase the volume fraction and particle density of the ordered δ＇（Al3Li） precipitates.

关 键 词：AL-LI合金 时效 模拟 形核机制 

分 类 号：TG156.92[金属学及工艺—热处理]