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Reversible formation of stacking faults in a nickel-based single crystal TMS-82 superalloy

Published online by Cambridge University Press:  16 December 2013

Xianzi Lv
Affiliation:
Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University, Jinan 250061, China
Jianxin Zhang*
Affiliation:
Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University, Jinan 250061, China
Hiroshi Harada
Affiliation:
High Temperature Materials Center, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047, Japan
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

Thermomechanical fatigue (TMF) tests have been carried out in a nickel-based single crystal TMS-82 superalloy, and the dynamic evolutions of dislocations and stacking faults have been studied in detail. It is found that the reversible formation of stacking faults is always associated with the loading orientation. Specifically, stacking faults expand under compression and shrink under tension due to the disappearance and appearance of dislocations during the TMF process. Stacking faults result from shear of γ′ precipitates by 1/3<112> dislocations, which arise from the decomposition of 1/2<110> matrix dislocations. The calculations of critically resolved shear stress to push dislocations that glide in the γ′ particles confirm the expansion of stacking faults under compression. However, under tension, dislocations in γ channel prevent 1/2<110> dislocations to enter γ′ cuboids and consequently, stacking faults shrink. Appearance and disappearance of dislocations during TMF cycling are associated with plastic deformation and annealing process, respectively.

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Articles
Copyright
Copyright © Materials Research Society 2013 

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References

REFERENCES

Pollock, T.M. and Argon, A.S.: Creep resistance of CMSX-3 nickel base superalloy single crystals. Acta Metall. Mater. 40, 130 (1992).CrossRefGoogle Scholar
Kear, B.H., Leverant, G.R., and Oblak, J.M.: An analysis of creep-induced intrinsic/extrinsic fault pairs in a precipitation hardened nickel-base alloy. Trans. ASM 62, 639650 (1969).Google Scholar
Leverant, G.R. and Kear, B.H.: The mechanism of creep in gamma prime precipitation-hardened nickel-base alloys. Metall. Trans. 1, 491498 (1970).CrossRefGoogle Scholar
Kear, B.H., Oblak, J.M., and Giamei, A.F.: Stacking faults in gamma prime Ni3(Al,Ti) precipitation hardened nickel-base alloys. Metall. Trans. 1, 24772486 (1970).CrossRefGoogle Scholar
Link, T. and Feller-Kniepmeier, M.: Shear mechanisms of the γ′ phase in single-crystal superalloys and their relation to creep. Metall. Trans. A 23, 99105 (1992).CrossRefGoogle Scholar
Feller-Kniepmeier, M. and Link, T.: Correlation of microstructure and creep stages in the <110> oriented superalloy SRR 99 at 1253K. Metall. Trans. A 20, 12331238 (1989).CrossRefGoogle Scholar
Shimabayashi, S. and Kakehi, K.: Effect of ruthenium on compressive creep of Ni-based single crystal superalloy. Scr. Mater. 63, 909912 (2010).CrossRefGoogle Scholar
Liu, F., Wang, Z.G., Ai, S.H., Wang, Y.C., Sun, X.F., Jin, T., and Guan, H.R.: Thermo-mechanical fatigue of single crystal nickel-based superalloy DD8. Scr. Mater. 48, 12651270 (2003).CrossRefGoogle Scholar
Kear, B.H., Giamei, A.F., Silcock, J.M., and Ham, R.K.: Slip and climb process in γ′ precipitation hardened nickel-base alloys. Scr. Metall. 2, 287294 (1968).CrossRefGoogle Scholar
Decamps, B. and Condat, M.: Use of the weak beam technique to study dislocations in hot worked nickel base superalloys. J. Spectrosc. Electron 11, 141148 (1986).Google Scholar
Feller-Kniepmeier, M. and Kuttner, T.: [011] creep in a single crystal nickel base superalloy at 1033K. Acta Metall. Mater. 42, 31673174 (1994).CrossRefGoogle Scholar
Kear, B.H., Giamei, A.F., Leverant, G.A., and Oblak, J.M.: Viscous slip in the Ll2 lattice. Scr. Metall. 3, 455460 (1969).CrossRefGoogle Scholar
Chen, Q.Z. and Knowles, D.M.: Mechanism of <112>/3 slip initiation and anisotropy of γ′ phase in CMSX-4 during creep at 750 °C and 750 MPa. Mater. Sci. Eng., A 356, 352367 (2003).CrossRefGoogle Scholar
Head, A.K., Humble, P., Clarebrough, L.M., Morton, A.J., and Forwood, C.T.: Computed Electron Micrographs and Defect Identification (North Holland, Amsterdam, Netherlands, 1973).Google Scholar
Knowles, D.M. and Chen, Q.Z.: Superlattice stacking fault formation and twinning during creep in γ/γ′ single crystal superalloy CMSX-4. Mater. Sci. Eng., A 340, 88102 (2003).CrossRefGoogle Scholar
Hirth, J.P. and Lothe, J.: Theory of Dislocations, 2nd ed. (John Wiley & Sons, New York, 1982).Google Scholar
Lall, C., Chin, S., and Pope, D.P.: The orientation and temperature dependence of the yield stress of Ni, (Al, Nb) single crystals. Metall. Trans. A 10, 13231332 (1979).CrossRefGoogle Scholar
Takeuchi, S. and Kuramoto, E.: Temperature and orientation dependence of the yield stress in Ni3Ga single crystals. Acta Mater. 21, 415425 (1973).CrossRefGoogle Scholar
Kear, B.H., Giamei, A.F., Leverant, G.R., and Oblak, J.M.: On intrinsic/extrinsic stacking pairs in the Ll2 lattice. Scr. Mater. 3, 123130 (1968).Google Scholar
Marchal, N., Flouriot, S., Forest, S., and Remy, L.: Crack-tip stress-strain fields in single crystal nickel-base superalloy at high temperature under cyclic loading. Comput. Mater. Sci. 37, 4250 (2006).CrossRefGoogle Scholar
Decamps, B., Raujol, S., and Coujou, A.: On the shearing mechanism of γ′ precipitates by a single (a/6) <112> Shockley partial in Ni-based superalloys. Philos. Mag. 84, 91107 (2004).CrossRefGoogle Scholar
Kovarik, L., Unocic, R.R., Li, J., Sarosi, P., Shen, C., Wang, Y., and Mills, M.J.: Microtwinning and other shearing mechanisms at intermediate temperature in Ni-based superalloys. Prog. Mater. Sci. 54, 839873 (2009).CrossRefGoogle Scholar
Nita, A., Lagerpusch, U., and Nembach, E.: CRSS anisotropy and tension/compression asymmetry of a commercial superalloy. Acta Mater. 46, 47694779 (1998).Google Scholar
Cao, F., Beyerlein, I.J., Addessio, F.L., Sencer, B.H., Trujillo, C.P., Cerreta, E.K., and Gray, G.T.: Orientation dependence of shock-induced twinning and substructures in a copper bicrystal. Acta Mater. 58, 549559 (2010).CrossRefGoogle Scholar
Ott, M. and Mughrabi, H.: Dependence of the high-temperature low-cycle fatigue behavior of the monocrystalline nickel-base superalloy CMSX-4 and CMSX-6 on the γ/γ′-morphology. Mater. Sci. Eng., A 272, 2430 (1999).CrossRefGoogle Scholar