Al-Si合金中α-Al依附于AlB_(2)异质形核的原子机制  

Atomic Mechanism of α-Al Heterogeneously Nucleating on AlB in Al-Si Alloy

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)

机构地区：[1]河南工学院材料科学与工程学院,河南新乡453000 [2]河南工学院电气工程学院,河南新乡453000

出　　处：《稀有金属材料与工程》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)。

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).

关 键 词：AlB_(2)晶体结构 AL-SI合金 异质形核 原子机制 EET电子理论 

分 类 号：TG146.21[一般工业技术—材料科学与工程]