双晶镍基高温合金定向凝固过程的结构演化

来源期刊：金属学报2010年第11期

论文作者：周亦胄 金涛 孙晓峰

文章页码：1327 - 1334

关键词：高温合金； 定向凝固； 枝晶生长； 晶粒竞争长大

Key words：superalloy； directional solidification； dendrite growth； competitive grain growth

摘    要：研究了双晶镍基高温合金IN792定向凝固过程的结构演化.对于汇聚生长晶粒,非择优取向枝晶在晶界处能够阻挡择优取向枝晶的生长,从而导致晶界从非择优取向晶粒向择优取向晶粒倾斜,竞争长大的结果是择优取向晶粒消失,非择优取向晶粒获胜:对于发散生长晶粒,晶界处会形成新的技晶,从而导致晶界从择优取向晶粒向非择优取向晶粒倾斜.竞争长大的结果是择优取向晶粒获胜,非择优取向晶粒消失.

Abstract: icrystal samples of Ni base superalloy IN792 were produced to study the structure evolution in directional solidification process.In the case of converging grains,the misaligned dendrites were able to block the better aligned dendrites at the grain boundary.The dendrite blocking leaded to inclination of the grain boundary from the misaligned grain to the better aligned grain.Thus,the better aligned grain was overgrown by the misaligned grain.In the case of diverging grains,dendrite development at the grain boundary leaded to inclination of the grain boundary from the better aligned grain to the misaligned grain.Consequently,the better aligned grain overgrew the misaligned grain.