Simulation study on thermodynamic, dynamic and structural transition mechanisms during the formation of Ca70Mg30 metallic glass

Abstract

The rapid quenching process of Ca70Mg30 alloy is simulated by using the molecular dynamics method. During the liquid-glass transition process, the thermodynamic, dynamic and structural transition mechanisms are investigated deeply, and the relations between glass transition temperatures determined by different methods are discussed. It is found that both the simulated structural factor of Ca70Mg30 metallic glass and glass transition temperature are consistent with the experimental results, and the icosahedral local configuration plays a critical role in the formation of Ca70Mg30 metallic glass. The dynamic property of supercooled liquid gradually deviates from the Arrhenius law and satisfies the MCT power law due to the cage effect formed by neighbor atoms. It is also found that the structural glass transition temperature is close to the dynamic one, and they are higher than the calorimetric glass transition temperature. The relationship between them and the ideal dynamic glass transition temperature satisfies the Odagaki relation.