Effects of Elevated Withdrawal Rate on the Microstructure and Segregation Behavior of a Nickel-base Single Crystal Superalloy

Zhou, Xuefeng; Chen, Guang; Feng, Yongbao; Li, Pei; Cheng, Jialin

doi:10.1016/s1875-5372(17)30145-5

Cited by 5 publications

(1 citation statement)

References 14 publications

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“…Where ΔG * is the critical nucleation work, rc is the critical nucleation radius, and ΔGv and ΔGs are the change of free energy per unit volume and change of surface free energy when γ' phase precipitates per unit volume respectively, and σγ-γ' is the specific surface energy or surface tension of γ phase and γ' phase. The lattice constants of γ and γ' are very close, and the interface between the two phases is a common lattice interface, which has smaller σγ-γ' and ΔG * , so γ' is easy to nucleate [15,16]. It is well known that, ΔGv is proportional to the degree of supersaturation and undercooling of the solid solution.…”

Section: Dendrite Growth Directionmentioning

confidence: 99%

Effect of Withdrawal Rate on Microstructure and Mechanical Properties of a Third Generation Nickel Based Single Crystal Superalloy

Guo

Liu

et al. 2022

MSF

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The influence of withdrawal rate (3, 4.5,6,9 and 12 mm/ min) on microstructure and high temperature rupture properties of A3 alloy was investigated by testing the microstructure and properties of the third generation nickel-based single crystal superalloy. The results show that with the increase of withdrawal rate, the dendrite spacing decreased exponentially, the segregation degree of main elements and the content of (γ + γ) eutectic structure decreased, and the size of γ phase decreased. After heat treatment, the eutectic structure was dissolved basically, and the segregation of the forming elements of γ phase is eliminated at different withdrawal rates. The size of γ phase in dendrite is smallest of 372.3μm at 4.5 mm/ min, the pore content is significantly larger than that of as-cast alloy, and decreased firstly and then increased with the increasing of withdrawal rate, which is 0.112% at 4.5 mm/ min and 0.182% at 3 mm/ min. The rupture life of the alloy at 1100 °C/140MPa is the longest at 4.5 mm/ min, which is mainly determined by the precipitation of TCP phase, pore content and γ size.

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Section: Dendrite Growth Directionmentioning

confidence: 99%