SIMULATING THE EFFECT OF POISSON RATIO ON METALLIC GLASS PROPERTIES

摘要

Recent work has shown that many metallic glass properties correlate with the Poisson ratio of the glass. We have developed a new model for simulating the atomistic behavior of liquids and glasses that allows us to change the Poisson ratio, while keeping the crystalline phase cohesive energy, lattice constant, and bulk modulus fixed. A number of liquid and glass properties are shown to be directly affected by the Poisson ratio. An increasing Poisson ratio stabilizes the liquid structure relative to the crystal phase, as indicated by a significantly lower melting temperature and by a lower enthalpy of the liquid phase. The liquids clearly exhibit two changes in behavior: one at low temperatures, associated with the conventional glass transition Tg, and a second, higher temperature change associated with the shear properties of the liquids. This second crossover has a characteristic, measurable change in the liquid structure.