基于3DAP及第一性原理的Al-Si-Cu-Mg合金团簇及沉淀演变  

Cluster and Precipitation Evolution in Al-Si-Cu-Mg Alloy Based on 3DAP and First-Principles

作　　者：田畅[1] 李荣德[1] 李润霞[1] 王瑞春[1] 曲迎东[1] 

机构地区：[1]沈阳工业大学辽宁省轻金属材料与工程重点实验室

出　　处：《特种铸造及有色合金》2014年第8期787-790,共4页Special Casting & Nonferrous Alloys

基　　金：辽宁省自然科学基金资助项目(201202166);辽宁省科技项目(LT2002004);辽宁省高等学校优秀人才计划资助项目(LR2011003)

摘　　要：基于Three Dimensional Atom Probe（3DAP）以及First-Principles对Al-Si-Cu-Mg合金中团簇及后续沉淀的演变过程进行了研究。3DAP试验表明,Al-1.0Si-1.5Cu-0.5Mg合金时效0.25h后基体中主要存在点状的Si-Si团簇、Si-Mg团簇、Si-Mg-Cu团簇,与第一性原理计算所表明的以上各结构中溶质原子间结合较强的结果相符,同时由于大量Si原子的扩散聚集,导致Si-Cu团簇结构出现;时效0.25-2h后基体中Si、Mg、Cu原子继续聚集,点状的Si-Si、Si-Cu、Si-Mg团簇长大并向针状的Si-Mg-Cu团簇演变;时效2-4h后,Si、Mg、Cu原子继续聚集,促进针状Si-Mg-Cu结构长大的同时,部分大尺寸的Si-Mg-Cu结构逐渐向板条状的Q′相转变,同时富Cu结构出现。The evolution behavior of cluster and subsequent precipitation in A1-Si-Cu-Mg alloys during ag ing procss were analyzed by means of three dimensional atom probe （3DAP） and first-principles calculations. 3DAP experiment shows that dot-like Si-Si clusters, Si-Mg clusters and Si-Mg-Cu clusters appear in AI-1.0Si-1.5Cu-0.5Mg alloy with aging at 175 ℃ for 0.25 h. First-principles calculation shows that the strong interaction exists between the solute atoms in structures mentioned. It consistents with the 3DAP experimental results. Meanwhile, the diffusion of Si atoms with a large number leads to the gen- eration of Si-Cu clusters. As Si, Mg, Cu atoms continued to precipitation with aging for 0. 25 h-2 h, dot-like Si-Si clusters, Si-Cu clusters, Si-Mg clusters are grown into needle-like Si-Mg-Cu clusters. In further aging evolution, the aggregation of Si, Mg, Cu atoms promotes the growth of Si-Mg-Cu struc- tures, and some Si-Mg-Cu structure is converted into lath-like Qr phase with generation of the Cu-rich structure.

关 键 词：3DAP 第一性原理 铸造AL-SI-CU-MG合金 时效 团簇 沉淀 

分 类 号：TG146.21[一般工业技术—材料科学与工程]