Molecular Dynamics Simulations of Structural and Mechanical Properties in MgSiO₃ Glass

Abstract

Molecular dynamics simulations of MgSiO3 glass have been carried out to study the structural and mechanical properties under uniaxial tension. The network structure consists of SiOx and MgOy units which link to others by corner‐, edge‐, and face‐sharing bonds. The Si‐rich and Mg‐rich regions exist in MgSiO3 glass. The stress–strain curves exhibit the elastic and plastic characteristics at the various strain rates. The transformations of SiOx and MgOy units occur with increasing strain, at which the corner‐, edge‐ and face‐sharing bonds among SiOx and MgOy units change. The Si‐rich and Mg‐rich regions increase with increasing strain. Not only the Mg–O bond length is easier to stretch than the Si–O bond length but also the O–Mg–O bond angle of MgOy units is easier to vary than that of SiOx units with the strain. The porosity is analyzed via the voids. The voids gather into the clusters of voids. The radii of voids increase with increasing strain. The number of big Mg‐voids increases under the tension and these voids coalesce to form large pores. These large pores do not coalesce to cause the fractured free surfaces. The formation of shear band was observed at the strain of 0.82.

Structure Analysis of Amorphous and Liquid Magnesium Silicate

“…There is change of the coordination number of Si and Mg atoms and intermediate range order structure in magnesium silicate melts under compression [2]. Molecular dynamics simulation of MgSiO3 liquid [12,13] clarified structural organization, network topology as well as the degree of polymerization under compression. In this work, we clarify structure of amorphous Mg2SiO4 at 0 and 40 GPa and compared with the one of liquid Mg2SiO4.…”

Study of the structure of MgSiO3 system under compression by using ring statistics and voronoi analysis

“…The same goes for Mg-Si pairs. The formation of face-sharing bonds has resulted in unequal density distribution and heterogeneity in the material [14,17,25]. The existence of Mg-rich regions under pressure is analyzed through the number of FO atoms and the formation of OMg x clusters [26].…”

Study of Dynamic Properties in MgSiO3 Liquid under Compression by Mean of Molecular Dynamics Simulation

“…Therefore, the information on the dynamics properties of MgSiO3 liquid is important for many applications in industry and materials science [1][2][3][4]. The structure, thermodynamic properties and transport properties of MgSiO3 meltswere investigated [5][6][7][8][9][10]. By using ab initio molecular dynamics simulation, Justin et al, [5] revealed that properties obtained from some alternative models show large relative errors compared to experiment, with viscosity.…”