三维稳态晶体生长的物理本质
Physical Essence of Crystal Growth in the Three-Dimension Stable State Problem
-
摘要: 考虑在均匀流场的作用下,分析了金属熔液凝固过程中晶体生长的三维稳态数学模型.应用傅里叶级数展开法,在周期性条件下得到了相应的八阶常微分方程的精确解析解,并确定了解中各系数之间的关系.该解揭示了在均匀流场的作用下,晶体生长呈现了一种周期性振荡式的模式,从理论上证实了固液界面前沿浓度呈现指数振荡衰减性是晶体生长的一个本质特性.Abstract: A corresponding three-dimensional steady state model concerned with dendrite growth is analyzed considering the influence of a uniform convection field. By using Fourier series, an eight-order ordinary differential equation is finally solved and an accurate analytic solution is obtained in a very neat form. The correlations among coefficients in the analytic solution are determined. The obtained solution shows that the crystal growth in the steady state presents cyclic oscillation attenuation along the dendrite growth direction under the influence of a uniform fluid field, and this feature is an intrinsic character.