The Element Segregation Between γ/γʹ Phases in a Ni-Based Single Crystal Superalloy Studied by 3D-APT and Its Potential Impact on Local Interfacial Misfit Strain

다국어 초록 (Multilingual Abstract)

Three-dimensional atom-probe tomography was used to characterize the γ/γʹ interface structure in a third-generation Nibasedsingle crystal superalloy with Re addition. It was found that an element-segregation layer with Re, Co and Cr wasformed in the γ phase close to the γ/γ′ interface, resulting in a more negative local interface misfit (− 0.29%) compared tothe measured result (− 0.16%) from high-resolution X-ray diffraction. Furthermore, the total reduction of interfacial freeenergy due to the solute atom segregation based on the Gibbsian interfacial excess was calculated to indicate that Re elementwas the most beneficial element in producing this more negative local misfit with the largest interfacial free energy reduction(13.67 ± 0.21 mJ/m2). Simultaneously, because of the co-segregation of Re, Co and Cr, and the depletion of Ni in the γphase close to the γ/γ′ interface, it was also deduced that some harmful topologically close-packed phases might be easierto nucleate and grow in the γ phase close to the γ/γ′ interface in service.

참고문헌 (Reference)

1 Y. Huang, "The effects of refractory elements on Ni-excesses and Ni-depletions at γ(f.c.c.)/γ′(L12)interfaces in model Ni-based superalloys: Atom-probe tomographic experiments and frst-principles calculations" 121 : 288-298, 2016

2 R. C. Reed, "The Superalloys : Fundamentals and Applications" Cambridge University Press 2006

3 S. Antonov, "Synchrotron in situ aging study and correlations to the γ′ phase instabilities in a high-refractory content γ–γ′Ni-base superalloy" 49 : 3885-3895, 2018

4 Q. Yue, "Stress dependence of the creep behaviors and mechanisms of a third-generation Ni-based single crystal superalloy" 35 : 752-763, 2019

5 Y. Amouyal, "Segregation of tungsten at γ′(L12)/γ(fcc)interfaces in a Ni-based superalloy : an atom-probe tomographic and frst-principles study" 93 : 201905-, 2008

6 X. X. Wu, "On the segregation of Re at dislocations in the γ’ phase of Ni-based single crystal superalloys" 4 : 109-114, 2018

7 R. Völkl, "Measurement of the lattice misft in the single crystal nickel-based superalloys CMSX-4, SRR99 and SC16 by convergent beam electron difraction" 46 : 4395-4404, 1998

8 L. Dirand, "Measurement of the effective γ/γ′ lattice mismatch during high temperature creep of Ni-based single crystal superalloy" 77 : 32-46, 2013

9 U. Brückner, "Local X-ray difraction analysis of the structure of dendrites in single-crystal nickel-base superalloys" 45 : 5223-5231, 1997

10 D. Isheim, "Interfacial segregation at Cu-rich precipitates in a high-strength low-carbon steel studied on a sub-nanometer scale" 54 : 841-849, 2006

11 S. Hayashi, "Interdifusion behavior of Pt-modifed γ-Ni+γ′-Ni3Al alloys coupled to Ni–Albased alloys" 36 : 1769-1775, 2005

12 S. Gao, "In situ investigation on the precipitation of topologically close-packed phase in Ni-base single crystal superalloy" 610 : 589-593, 2014

13 P. Caron, "High γʹ solvus new generation nickel-based superalloys for single crystal turbine blade applications" 2000 : 738-746, 2000

14 M. Huang, "Coupling between Re segregation and γ/γ′ interfacial dislocations during high-temperature, low-stress creep of a nickel-based single-crystal superalloy" 76 : 294-305, 2014

15 R. Srinivasan, "Atomic scale structure and chemical composition across order-disorder interfaces" 102 : 086101-, 2009

16 A. Mottura, "Atom probe tomography analysis of the distribution of rhenium in nickel alloys" 58 : 931-942, 2010

17 X. Jiang, "An materials informatics approach to Ni-based single crystal superalloys lattice misft prediction" 143 : 295-300, 2018

18 P. J. Warren, "An atom probe study of the distribution of rhenium in a nickel-based superalloy" 250 : 88-92, 1998

19 Z. Zhu, "A model for the creep deformation behaviour of nickel-based single crystal superalloys" 60 : 4888-4900, 2012