单晶高温合金的选晶行为

摘要

对高温合金单晶选晶生长工艺进行了实验研究， 揭示了螺旋选晶器和缩颈选晶器的选晶原理。 实验结果表明， 在螺旋选晶器中， 晶体横向择优生长与螺旋结构的耦合作用， 形成连续选晶过程， 是螺旋选晶的主要原理， 其选晶作用良好；而在缩颈选晶器中， 几乎只存在单一的机械阻隔选晶行为， 多重缩颈结构对于改善选晶作用并不明显， 选晶效果不好。%The single crystal selection processes of superalloy in the helix selector and thin-neck selector were studied. The results indicate that the main grain selection mechanism of the helix selector is that the easy growth direction of the cubic crystal coupled with the helical structure of the selector. Helix selector combines with the characteristics of thin-neck and angled grain selector in structure. In thin-neck selector， there is only the grain selection function of mechanical restricting， and the design of multiple thin necks is not beneficial to improving the grain selection effect.