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本文研究开发了柱状晶区域向等轴晶区域转变的新理论。本文提出,枝晶生长的前端成长为自由晶;由于自然对流,这些结晶在熔融的液体中生长。这些自由晶迅速长大或迅速增加的话,则将会随着凝固的前沿阻止柱状晶的生产。铸型的冷却速度和凝固工艺的动力学决定了自由晶的生长速度。根据理论推定,冷却速度愈快,转变愈容易完成。本文还将上述情
In this paper, a new theory of the transition from columnar region to equiaxed zone has been developed. This paper proposes that the front end of dendrite growth grow into free crystals; these crystals grow in the molten liquid due to natural convection. The rapid growth or rapid increase of these free crystals will prevent the production of columnar crystals along the solidification frontier. The cooling rate of the mold and the kinetics of the solidification process determine the growth rate of free crystals. According to the theory, the faster the cooling rate, the easier it will be to complete the transition. This article will also be the situation