Modification of Eutectic Si in Al-Si-(Ba) Alloy by Inducing a Novel 9R Structure in Twins

Xuechao Sha; Xuefei Chen; Huiyan Ning; Lirong Xiao; Dongdi Yin; Lin Mao; Jiang Zheng; Hao Zhou

doi:10.3390/ma11071151

Modification of Eutectic Si in Al-Si-(Ba) Alloy by Inducing a Novel 9R Structure in Twins

Materials (Basel). 2018 Jul 6;11(7):1151. doi: 10.3390/ma11071151.

Authors

Xuechao Sha¹, Xuefei Chen^{2

3}, Huiyan Ning^{4

5}, Lirong Xiao⁶, Dongdi Yin⁷, Lin Mao⁸, Jiang Zheng⁹, Hao Zhou^{10

11}

Affiliations

¹ Beijing Key Lab of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124, China. shaxuechao@emails.bjut.edu.cn.
² Nano and Heterogeneous Materials Center, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China. chenxuefei@lnm.imech.ac.cn.
³ State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, 15 Beisihuan West Road, Beijing 100190, China. chenxuefei@lnm.imech.ac.cn.
⁴ School of Mechanical and Electrical Engineering, Heilongjiang Institute of Technology, Harbin 150050, China. ninghuiyan2000@163.com.
⁵ School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China. ninghuiyan2000@163.com.
⁶ Beijing Key Lab of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124, China. xiaolr620@126.com.
⁷ Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Sichuan 610031, China. ahnydd@swjtu.edu.cn.
⁸ Shanghai Institute for Minimally Invasive Therapy, School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China. linmao@usst.edu.cn.
⁹ International Joint Laboratory for Light Alloys (Ministry of Education), College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China. jzheng@cqu.edu.cn.
¹⁰ Beijing Key Lab of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124, China. hzhou511@njust.edu.cn.
¹¹ Nano and Heterogeneous Materials Center, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China. hzhou511@njust.edu.cn.

Abstract

The change of twinning morphology plays an important role in the modification of Al-Si alloys, which are widely used in industrial applications. However, the interpretation of this change is still insufficient. In this work, the microstructure of twins was investigated in two kinds of Al-Si alloys with different additions of Ba using high-resolution transmission electron microscopy (HRTEM). Unlike the normal {111} twin that exists in Ba-free alloy, discontinuous twins and multiple twins were observed in the Ba-containing alloy. In addition, the 9R structure formed by the dissociation of twins was firstly observed at the turning of discontinuous twins and the intersection of multiple twins in Al-Si alloys.

Keywords: 9R structure; Ag-Si alloy; HRTEM; modification; twinning morphology.