金属及合金非平衡凝固的热力学行为分析

THERMODYNAMIC BEHAVIOR OF NONEQUILIBRIUMSOLIDIFICATION OF METALS AND ALLOYS

运用Ｐｒｉｎｇｏｇｉｎｅ的非平衡热力学理论，分析了金属及合金在非平衡凝固条件下凝固的热力学行为，提出了非平衡凝固时，获得亚稳组织的临界过冷度方程。运用此模型计算了合金的玻璃转变点，并分析了各物性参量对玻璃转变点的影响，结果与实验有较好的吻合。由此可以看出，用非平衡热力学理论描述金属及合金的非平衡凝固是可行的。

The thermodynamic behavior of nonequilibrium solidification of metals and alloys has been analysed, and an equation met by the critical reduced supercooling at which the solidification system may become unstable and the solidification product will be not the equilibrium structure but the metastable structure was proposed. Based on this model, the glass transition temperatures of some metals and alloys have been calculated and the influences of material parameters on glass transition temperature have been discussed. The results are in good agreement with the experiments. It has been shown feasible to describe the nonequilibrium solidification by using Pringogine's nonequilibrium thermodynamic theory.