相场法研究温度对非晶一次晶化过程中微观组织演化及生长动力学的影响

Phase Field Method Study on Microstructure Evolution and Growth Kinetics under Different Temperature during Primary Crystallization of Amorphous

尽管有大量的实验对非晶一次晶化进行研究,但是由于受到实验条件的限制,很难对非晶一次晶化过程进行实时跟踪观察。近年来,发展起来的相场方法充分考虑了非晶前驱体在转变过程中随成分变化的局部扩散特性,并能实时反映非晶一次晶化过程中微观组织演化过程,从而得到广泛应用。采用相场方法模拟研究温度对非晶一次晶化过程中微观组织演化和生长动力学的影响。结果表明:不同温度情况下,非晶一次晶化后期出现晶粒合并生长,随着演化时间的增加晶粒数量逐渐减少,晶粒尺寸逐渐增大。晶化分数随着演化时间和温度的增加而增加,温度越高,相同演化时间内的晶化分数越高。不同温度情况下所对应的生长指数均小于1,这表明非晶晶化方式为一次晶化,说明温度对非晶晶化方式无影响。

Although there were a large number of experimental researches on the primary crystallization of amorphous materials,it was difficult to track and observe the primary crystallization process in real time due to the limitations of experimental conditions.The phase field method was widely used due to the fully consideration of the local diffusion properties of the amorphous precursor with the variation of the composition during the transformation and the reflection of the microstructure evolution process in a crystallization process in real time.The phase field method was employed to simulate the influence of temperature on the microstructure evolution and growth kinetics of amorphous alloys during the primary crystallization process.The results show that under different temperature conditions,the combined growth occurs during the later stage of primary crystallization process of the amorphous alloy.As the evolution time increases,the number of grains gradually decreases,and the grain size gradually increases.The crystallization fraction increases with the increase of evolution time and temperature.The higher the temperature,the higher the crystallization fraction within the same evolution time.The growth index corresponding to different temperatures are less than 1,indicating that the mode of crystallization method is primary crystallization.The temperature has no significant effect on the mode of crystallization.