Abstract Newly designed Ti-47Al-6Nb-0.1C at.% alloy was directionally solidified by cold crucible under 45 kW at the growth rate of 5–16.67 μm/s. The macro/microstructure evolution, room-temperature tensile property and creep behavior are investigated. The results show that this alloy was well directionally solidified by cold crucible at the growth rate of 5–11.67 μm/s, and they display primary β solidification at this growth-rate range. It is also found that the lamellar spacing is mainly controlled by growth rate, and the lamellar spacing decreases with the increasing of growth rate according to relationship d = 1751 V − 0.58 . Moreover, the extent of microsegregation increases with the increasing of growth rate, and thus the effect of microsegregation on creep behavior is discussed. After controlling directional solidification process at growth rate of 5–8.33 μm/s, this alloy exhibits good creep properties with creep life more than 800 h at 800 °C/200 MPa, and the acceptable room-temperature tensile property with yield strength 436–452 MPa and elongation 1.62–1.68%.

中文翻译：

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Ti-47Al-6Nb-0.1C合金定向凝固组织控制及蠕变行为

摘要 新设计的Ti-47Al-6Nb-0.1C at.%合金通过冷坩埚在45 kW下以5-16.67 μm/s的生长速率定向凝固。研究了宏观/微观结构演变、室温拉伸性能和蠕变行为。结果表明，该合金在冷坩埚中以 5–11.67 μm/s 的生长速率进行了良好的定向凝固，并且在该生长速率范围内显示出初级 β 凝固。还发现层间距主要受生长速率控制，层间距随着生长速率的增加而减小，关系式d = 1751 V − 0.58 。此外，微观偏析的程度随着生长速率的增加而增加，因此讨论了微观偏析对蠕变行为的影响。