Effects of Solidification Defects on Nanoscale Mechanical Properties of Rapid Directionally Solidified Al-Cu Alloy: A Large Scale Molecular Dynamics Study
Abstract
Directional solidification of Al-11 at % Cu is investigated by molecular dynamics (MD) simulations utilizing second nearest neighbor modified embedded atom method (2NN-MEAM) interatomic potential. The condition for directional solidification is produced by imposing dissimilar temperatures at the model boundaries along the [1 0 0] solidification direction to create a temperature gradient. During solidification, the solid-liquid front travels through the Al-Cu liquid along the [1 0 0] direction towards the high temperature end. At the initial stages of solidification, several solidification defects such as twins, stacking faults, and grain boundaries form. As directional solidification progresses, grains elongate along the solidification direction, and at the final stages of solidification no new defects or grain boundaries form. The elongated grain boundaries form a few layers with lamellar like structures along [1 0 0]. When the solidified polycrystalline is deformed in the [0 0 1] direction, glide of partial dislocations happen around the grain boundaries, whereas during elongation along [1 0 0] some defects from in the Al-Cu matrix. Since formation of defects requires more energy, the solidified samples show a higher tensile strength and strain when deformed along the [1 0 0] solidification direction.
Recommended Citation
A. Mahata and M. Asle Zaeem, "Effects of Solidification Defects on Nanoscale Mechanical Properties of Rapid Directionally Solidified Al-Cu Alloy: A Large Scale Molecular Dynamics Study," Journal of Crystal Growth, vol. 527, article no. 125255, Elsevier, Dec 2019.
The definitive version is available at https://doi.org/10.1016/j.jcrysgro.2019.125255
Department(s)
Materials Science and Engineering
Keywords and Phrases
A1. Computer simulation; A1. Defects; A1. Directional solidification; A1. Nucleation; B1. Alloys
International Standard Serial Number (ISSN)
0022-0248
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 Elsevier, All rights reserved.
Publication Date
01 Dec 2019
Comments
National Science Foundation, Grant CMMI 1537170