Wang Wei, Guo Fengxiang, Gai Zhigang, Zhang Tao, Tang Jianguo, Tian Xuelei, Liu Wenqing
College of Materials Science and Engineering, the National Base of International Science and Technology Cooperation on Hybrid Materials, Qingdao University, 308, Ningxia Road, Qingdao 266071, China.
Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Marine Monitoring Instrument Equipment Technology, National Engineering and Technological Research Center of Marine Monitoring Equipment, Qingdao 266001, China.
Materials (Basel). 2018 Aug 10;11(8):1404. doi: 10.3390/ma11081404.
In order to investigate the competitive interaction between nanoparticles and twin, the eutectic Si microstructures in Al⁻10Si (wt. %) base alloys with exclusive and combined addition of Sr and Sb are characterized by combined TEM and atom probe tomography (APT). The chemical short range order in Sb⁻Sb and Sb⁻Sr pairs is revealed by ab initio molecular dynamics simulation, which promotes the formation of clusters and nanoparticles. The coexistence of nanoparticles and twins is observed in Sb containing alloys, with a negative correlation in the corresponding number density, owing to the competitive stacking of precursors and individual atoms at the solid⁻liquid interface. Large size particles around 70 nm with a uniform distribution of Sr atoms are formed in Al⁻10Si⁻0.35Sb⁻0.015Sr (wt. %) alloys, due to the precursor aggregation and homogeneous nucleation in the droplets that nucleation are depressed. A model for the formation of nanoparticles and their interaction with twins is proposed.
为了研究纳米颗粒与孪晶之间的竞争相互作用，采用透射电子显微镜（TEM）和原子探针断层扫描（APT）相结合的方法，对单独添加和同时添加Sr和Sb的Al-10Si（质量分数）基合金中共晶硅微观结构进行了表征。通过第一性原理分子动力学模拟揭示了Sb-Sb和Sb-Sr对中的化学短程有序，这促进了团簇和纳米颗粒的形成。在含Sb合金中观察到纳米颗粒和孪晶共存，由于前驱体和单个原子在固液界面的竞争堆积，它们的数量密度呈负相关。在Al-10Si-0.35Sb-0.015Sr（质量分数）合金中形成了尺寸约为70nm、Sr原子分布均匀的大尺寸颗粒，这是由于液滴中前驱体聚集和均匀形核，使形核受到抑制。提出了纳米颗粒形成及其与孪晶相互作用的模型。
