| Recent years, glass-ceramics made of iron tailings, red mud, slag, basalt and other raw materialshas has been extensive researched. For the greater economic and environmental benefits, the researchers are devoted to improve the the utilization of the raw materials of the glass-ceramics. As a important composition of the raw materials, Iron oxide was of particular concern. Molecular dynamics method has advantage in the research of microstructure of the material. It has been widely used in various field. It plays an considerable role in promoting the development of the glass-ceramics, which analyze the structure of glass-ceramics in microscopic scale, for a good understanding of the role played by iron oxide.This paper studyed the steps of molecular dynamics simulation for CaO-Al2O3-SiO2-Fe2O3glass-ceramic system by Materials Studio software,such as the construction of the initial model,the selection of potential function,the calculate progress. After determining a series of optimum parameters and completing the simulation process successfully,this paper studyed the effects of Fe2O3for the system microstructure.In the initial model, the best Parameters for the CaO-Al2O3-SiO2-Fe2O3glass-ceramics are:800K,10,2.7g/cm3(Temperature, number of Amorphous, and Density, respectively). It also simulate and verify the potential function parameters for such glass-ceramics discoveried by Alfonso Pedone and etc. In this system, cooling system using segmentation mechanism, NVT ensemble conditions, the integration step process set lfs are selected. Result:in the glass-ceramics system of CaO-Al2O3-SiO2-Fe2O3(Ca:Al:Si=1:1:3), the cation of the oxygen ions is in order of force Si4+> Al3+>Fe34>Ca2+. As Ca2+is lack of capacity of donoring the balance charge and the accept capacity of Fe3+is lower than that of Al3+andSi4+i Fe3+is difficult to formate [FeO4],which is unstable and not consistent. Fe3+rarely impact the connection among the unit of the system network, and does not undermine the overall structure of the network, but will cause the shape change of [AlO4] cell structure, while the [SiO4] is stability enough to avoid the effect of Fe3+. In the systems, it exists a very little amount of {Si}5and three oxygen, generated by the competing O2-for the cation, in which Fe3+ is mainly competing the bridge oxygen in the Al-O-Al. When the amount of Fe3+is small, the number of three oxygen increases as the increasing of the Fe3+. The number of three oxygen is maximum when the quality of Fe2O3is5.71%of the system, and then as the increase of Fe3+, the number of the three oxygen begins to decrease. Three oxygen system greatly reduces the overall activity of oxygen diffusion capacity and Al3+is very similar. Generally, the system activity strength of the order of the ion is Ca2+> Fe3+> Al3+> O2-> Si4+, the system Fe3+will [AlO4],[FeO4] structure is formed to provide charge balance, some of Fe3+and the non-bridging oxygen connection, the activity in the system will be very strong, and diffusion capacity close to Ca2+. |
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