Abstract Assisted by the mold preinstalled an alumina tube into seed segment, the influence of the original primary dendrite spacing of seed on the formation of stray grains at melt-back region was investigated during Ni-based single crystal casting using seeding method. The results showed that the interface reaction between the seed and mold as well as the formation of stray grains at the surface of seed were avoid using an alumina tube with surface roughness of 0.35 μm as the mold inner wall. As the original primary dendrite spacing of the seed decreased to less than 201 μm, the morphology of un-melted solid phase in semi-solid zone changed from isolated dendrite stem to the complex network, resulting in the inhibition of the formation of stray grains inside of the seed. The seed with original primary dendrite spacing of 201 μm was also successfully re-used to fabricate single crystal casting.

中文翻译：

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抑制回熔区杂散晶粒的再利用以制备镍基单晶高温合金

摘要 在晶种段内预装氧化铝管的模具辅助下，采用晶种法研究了Ni基单晶铸造过程中晶种原始初始枝晶间距对回熔区杂散晶粒形成的影响。结果表明，使用表面粗糙度为0.35 μm的氧化铝管作为模具内壁可以避免种子与模具的界面反应以及种子表面杂散晶粒的形成。随着晶种的原始初生枝晶间距减小到小于201 μm，半固态区未熔融固相的形态由孤立的枝晶茎转变为复杂的网络，从而抑制了内部杂散晶粒的形成。种子的。