强磁场对丁二腈定向生长形貌的影响

Influences of High Magnetic Field on Morphological Evolution of Pure Succinonitrile During Directional Solidification Process

在无磁场以及1T磁场强度条件下,对纯度为99.927%的丁二腈定向凝固过程的生长形貌进行实时观察,通过测量不同试验条件下丁二腈的生长速度、一次枝晶间距、尖端半径等主要特征参数,对磁场下丁二腈定向凝固过程所受的影响进行了理论分析。在无磁场条件下,随着温度梯度的增大,丁二腈模拟金属定向凝固组织为斜枝晶;生长速度几乎不受影响;一次枝晶间距和二次枝晶臂间距减小;生长尖端半径增大。温度梯度不变时,对丁二腈施加磁场强度为1T的磁场,此时丁二腈生长形貌依旧为斜枝晶;生长速度降低;一次枝晶间距普遍增大;生长尖端半径增大。

The growth morphology of directional solidification in the butanedinitrile of 99.927%purity was observed in real time with or without a magnetic field of 1T.The effect of magnetic field on directional solidification of butanedinitrile was theoretically analyzed by measuring the main characteristic parameters such as growth rate,the primary dendrite spacing and tip radius under different temperature gradients and different magnetic field strengths.Under the condition of no magnetic field,with the increase of temperature gradient,directional solidification organization of butanedinitrile was always oblique dendrite;the growth rate was almost unaffected;the primary and secondary dendrite arm spacing reduced then;the radius of growth tip increased accordingly.When the temperature gradient was constant,a magnetic field of 1T applied to butanedinitrile,at this time,the growth morphology of butanedinitrile was still oblique dendrite;the growth rate decreased;the primary dendrite spacing generally increased;the radius of growth tip also increased.