Isothermal solidification behavior of typical Ni3Al base superalloy IC6
来源期刊：中国有色金属学报(英文版)2000年第4期
论文作者：汪小平 郑运荣 肖程波 王蓓蕾 韩雅芳
文章页码：430 - 434
Key words：Ni3Al base superalloys; solidification process; microstructures;δ-Ni0.76Mo1.24phase
Abstract: Solidification sequence of a typical Ni3Al base superalloy IC6 was studied by isothermal solidification method. The results show that the liquidus, solidus, melting point of the boride and secondary γ′precipitation temperature of the IC6 alloy are notably higher than those of conventional nickel base superalloys because of its higher Mo content. There is no eutectic γ′precipitation during the solidification of the alloy, but a kind of Mo-richδ-Ni0.76Mo1.24primary phase precipitates together with γ phase by eutectic reactionL′→δ+γ+L″in the temperature range of 1 573~1 553 K, this δ- Ni0.76Mo1.24 phase has a primitive orthorhombic structure witha=0.917 8 nm,b=0.914 2 nm andc=0.882 8 nm. Moreover, Al element of the alloy segregates in dendritic areas during isothermal solidification process, which causes secondary γ′phase precipitate in the order of precedence from dendrites to interdendrites.
