液态金属的初始状态对凝固微结构影响的模拟研究

A SIMULATION STUDY FOR THE EFFECTS OF INITIAL CONDITIONS OF LIQUID METALS ON SOLIDIFICATION MICROSTRUCTURES

采用分子动力学方法对液态金属Ａｌ在不同的初始状态下，以相同急冷速率凝固的过程进行模拟跟踪研究，发现：在玻璃转变温度Ｔｇ以上（即过冷液态）时，系统的微结构组态情况基本一致，相差甚微；但在Ｔｇ以下时，不同的初始液态微结构对其固态微结构有明显的影响；且在Ｔｇ处各种固态微结构之间的差别发生突发性的变化。这一结果对于深入理解液－固微结构之间的转变关系，具有一定的重要意义。

The effects of different initial conditions of liquid metal Al on the solidification microstructures during the same rapid solidification process have been studied using molecular dynamics simulations. From the results, it has been found that under different initial conditions:(1) above the glass transition temperature T g (namely in suppercooled-liquid states), the microstructures in the system are almost in the same state; (2) below the glass transition temperature T g , the microstructures in the system have remarkable variations; (3) at temperature T g , the effects of different initial conditions are occurred suddenly. These results will give us a new way to understand the microstructure transitions of liquid metals from liquid to solid states.