The Melt Viscosity Characteristic Of Molecular Dynamics Simulation For RO/R₂O-Al₂O₃-SiO₂

Conducting relevant research work on glass ceramics, most researchers are dedicated in investigating the micro-structure and its effect on the properties of glass-ceramics through experiments. RO/R2O-Al2O3-SiO2 acts as a typical high-temperature melt glass-ceramic systems, it can be better for us to understand the network structure and the structure effect of RO/R2O for network through analyzing its structure on the microscopic scale. Furthermore, this research provides significant contribution on the research and development of glass ceramics micro-structure in the future.It is an efficient method for the network structure of high temperature melts utilizing molecular dynamics simulation. The relevant molecular dynamics software, Materials Studio, by which we conduct theoretical simulation on the network structure of high temperature melt based on conducting initial models, optimizing formulation, arithmetic calculation, and measuring parameters. Besides, we compare with the micro effects of network structure and viscosity of high temperature melts upon different RO/R2O alkali metal oxidants and SiO2 content.After the study compared by Na+、Ca2+、two alkali metals for high-temperature melt silicate network structure and the statistical analysis of the bond lengths and angles bridging oxygen content, It was found that in the same proportion NAS system under high temperature random network structure should be loose network structure than the CAS system in a multi-0 of the absolute number of conditions, NAS system does not form more bridging oxygen, obtained alkali metal of Na+ on the solution of the isolated high-temperature melt than alkali metal Ca2+ is more intense.By changing the content of SiO2,computer simulation study found that with increasing Si content, the bridge oxygen content in the system increases rather than non-bridging oxygen content decreased, the number of [SiO4], [SiO5] increases while [AlO4] decreased; The melt shear viscosity increased with the macro Si content increases, with the increase of SiO2 content, the internal network structure of the melt to reduce the degree of disorder, increase the number of polymer, the network structure more perfect, so the melt macroscopic viscosity increases. NAS system melt bridge oxygen content, the amount is less than the CAS system tetrahedral melt, compared to the network structure is concerned; CAS lines melt network structure changes with the addition of Si melt more perfect than the NAS.