摘要
利用带有对流驱动系统的定向凝固装置,研究了液相稳定流动时透明合金SCN-2wt-％Ace定向凝固的动态过程.结果表明:流动显著改变定向凝固柱状晶的一次间距枝晶的间距增大,主要是流动与枝端浓度场耦合作用的结果;胞晶的间距变小。
An experimental apparatus, which has a convection generator and anaid-heater, is developed for the study of the effect of stable laminar liquid flow on thedirectional solidification process by the use of transparent alloy SCN-2wt-% Ace. The flowis perpendicular to primary arms. By,in-situ observation and photographing at different spe-cific moments, it has been found that such a flow can cause a great change in primaryspacings of constrained columnar crystals: for cells, the spacings become smaller; but fordendrites, they become larger. The former is mainly due to the tilted growth of upstreamsidebranches, while the latter is mainly due to the coupling effect of liquid flow with solutal fieldaround dendrite tips. The faster the liquid flows, the further smaller the cells space and thefurther larger the dendrites space.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
1993年第4期A147-A152,共6页
Acta Metallurgica Sinica
基金
国家自然科学基金
关键词
液相强迫流动
定向凝固
枝晶间距
forced liquid flow
directional solidification
dendrite spacing
cell spacing
