Ca（70）Mg（30）金属玻璃形成过程热力学、动力学和结构特性转变机理的模拟研究

徐春龙; 侯兆阳; 刘让苏

长安大学应用物理系,西安,710064

湖南大学物理与微电子科学学院,长沙,410082

Simulation study on thermodynamic, dynamic and structural transition mechanisms during the formation of CaToMg3o metallic glass

摘要: 采用分子动力学方法对Ca（70）Mg（30）合金快速凝固玻璃形成过程进行了计算机模拟,深入分析了液-固玻璃转变过程热力学、动力学和结构特性的转变机理,对不同方法所确立的玻璃转变温度之间的关系进行了探讨.结果表明：本模拟计算所获得的Ca（70）Mg（30）金属玻璃的结构因子和玻璃转变温度均与实验结果符合,而且二十面体局域结构对Ca（70）Mg（30）金属玻璃的形成起决定性作用.由于周围原子形成的瞬时＂笼子效应＂,过冷液体动力学特性逐渐偏离Arrhenius规律而满足模态耦合理论的幂指数规律.动力学玻璃转变温度接近于微观结构玻璃转变温度,但高于热力学玻璃转变温度;而且它们与理想动力学玻璃转变温度之间满足Odagaki关系.

关键词:

Abstract: The rapid quenching process of CavoMgao alloy is simulated by using the molecular dynamics method. During the liquidglass 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 CaToMg30 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 CaToMg30 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.

Ca（70）Mg（30）金属玻璃形成过程热力学、动力学和结构特性转变机理的模拟研究

长安大学应用物理系,西安,710064

湖南大学物理与微电子科学学院,长沙,410082

关键词:

Simulation study on thermodynamic, dynamic and structural transition mechanisms during the formation of CaToMg3o metallic glass

长安大学应用物理系,西安,710064

湖南大学物理与微电子科学学院,长沙,410082

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