一方向凝固した純アルミニウム柱状晶の優先成長方位

抄録

Columnar crystals of pure aluminum were competitively grown at various G/R in <100>, <110> and <111> directions from seed crystals. Crystals having <111> growth orientation preferentially grow under such a condition that a planar solid-liquid interface advances at high G/R. Crystals having <100> growth orientation, on the other hand, preferentially grow similarly as dendritic growth under such a condition that the interface forms hexagonal or broken cells at low G/R. When the interface forms irregular or elongated cells, <100>, <110> and <111> orientations stably advance accompanying by little preference. The <111> and <100> orientation preferences are built up in the mechanisms that a crystal extends to the direction perpendicular to the growth direction and that a crystal prejects ahead of the mean interface respectively. The preferred growth is explained on the basis of the {111} platelet growth theory.