摘要
利用固体与分子经验电子理论分别计算了α-Al,AlB_(2)与(Al-Si)B_(2)的价电子结构与结合能。结果表明,AlB_(2)最外层的Al-Al原子层相对不稳定,随着Al-Si熔体中Si含量的增加,α-Al和AlB_(2)的结合能均降低。根据计算结果,提出了Al-Si合金中α-Al在AlB_(2)上异质形核的一种全新原子机制。加入Si后,一定量的Si原子进入AlB_(2),在AlB_(2)表面形成稳定的Al-Si二元原子结构层,提高了AlB_(2)表面的稳定性。这种稳定的二维Al-Si原子层在随后的异质形核过程中起着重要的过渡作用,是AlB_(2)成为α-Al有效异质核心的原子机制。
The valence electron structure and cohesive energy of α-Al, AlB_(2) and(Al-Si)B_(2) crystals were calculated using the empirical electron theory(EET) of solids and molecules. The calculated results indicate that Al-Al atomic layer on outermost surface of AlB_(2) is relatively unstable and the cohesive energy of both α-Al and AlB_(2) decrease with increase of Si content in Al-Si melt. According to the calculated results, a novel atomic mechanism of α-Al heterogeneously nucleating on AlB_(2) in Al-Si alloy is explored. After adding additional Si, a certain amount of Si atoms enter into AlB_(2), which results in formation of a stable Al-Si binary atomic structure layer on AlB_(2) surface and finally improves the stability of AlB_(2). This two-dimensional Al-Si atomic layer plays an important transition role in the subsequent heterogeneous nucleation process, which is responsible for the atomic mechanism of nucleation of α-Al attached to AlB_(2).
作者
苏光
张爱民
韦佳宏
Su Guang;Zhang Aimin;Wei Jiahong(Department of Material Science and Engineering,Henan Institute of Technology,Xinxiang 453000,China;Department of Electrical Engineering and Automation,Henan Institute of Technology,Xinxiang 453000,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2021年第6期1964-1970,共7页
Rare Metal Materials and Engineering
基金
Training Program of Young Scholar in College and University of Henan Province (2017GGJS168)
PHD Scientific Research Initial Foundation of Henan Institute of Technology (KQ1848)。
