Elastic and structural properties of low silica calcium aluminosilicate glasses from molecular dynamics simulations

• Published in: Journal of non-crystalline solids 2018-11, Vol.499, p.142-152
• Main Authors: Jabraoui, Hicham, Badawi, Michael, Lebègue, Sébastien, Vaills, Yann
• Format: Article
• Language: English
• Subjects: Chemical Sciences; Low silica aluminosilicate glasses; Material chemistry; Mechanical properties; Molecular dynamics simulations; Structural properties
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2018.07.004

The elastic constants and the structural of low silica calcium aluminosilicate glasses with a low content of silica (5–25 mol%) and [CaO]/[Al2O3] =2, are investigated using molecular dynamics simulations. In particular, their elastic constants are calculated using two methods: a standard approach at zero temperature and another method designed to work at finite temperature. We show that while they both reproduce qualitatively the experimental behavior, only the method taking temperature into account provides a quantitative agreement with the experimental values. Therefore, taking temperature into account in the determination of elastic constants seems necessary to give a satisfactory account of the mechanical properties of these materials. In accordance with the experimental results, our molecular dynamics calculations show values of elastic constants that decrease with increasing amount of silica in the vitreous network. Then, the structure of the glasses is analyzed in term of pair distribution functions, oxygen kinds, and the parameter of short-range order, and discussed in correlation with the available experimental data. An overall good agreement is obtained with the calculated structure and the experimental data. •Low silica calcium aluminosilicate glasses (LSCAS) are studied using MD simulations.•Two methods (zero and finite temperature) to compute elastic constants are tested.•Structural properties as the linkage of O atoms nicely agree with experimental data.•Relationship between elastic constants and structural properties is discussed.•If silica content increases, free volume increases leading to low elastic constants.