|
|
Influence of Small Misorientation from <111> on Creep Properties of a Ni-Based Single Crystal Superalloy |
HU Bin,LI Shusuo,PEI Yanling,GONG Shengkai( ),XU Huibin |
School of Materials Science and Engineering, Beihang University, Beijing 100191, China |
|
Cite this article:
HU Bin,LI Shusuo,PEI Yanling,GONG Shengkai,XU Huibin. Influence of Small Misorientation from <111> on Creep Properties of a Ni-Based Single Crystal Superalloy. Acta Metall Sin, 2019, 55(9): 1204-1210.
|
Abstract Single crystal nickel-based superalloys have been widely used in high temperature structural materials applications including blade parts of aero-engines and gas turbines due to their excellent mechanical properties in service. Although commercial single crystal superalloy blades are in [001] orientation, misorientation deviations are inevitable in industrial productions and work blades frequently have to endure complex stress states caused by their complicated shapes and temperature gradients. Therefore, it is of great significance to study the creep behavior of single crystal superalloys with different orientations for the design of engine blades. The anisotropic creep properties of a nickel-based single crystal superalloy with different orientations near <111> were investigated under 760 ℃ and 650 MPa. It is found that specimens with the smallest deviation from <111> orientation exhibit best creep strength because of the relatively low Schmid factors of both {111}<110> and {111}<112> slip systems. With the increase of orientation deviate from [11] to [011], creep properties decrease more significantly compared with the deviation from [11] to [001]. All samples deviate from <111> within 20° exhibit poor strain hardening. While orientations toward [11]-[001] boundary have a distinct incubation creep stage with relatively low initial creep rate. Further dislocations and lattice rotation analysis showed that the dominant slip systems are {111}<110> for specimens with minimum deviations. The stress is almost uniformly distributed in three γ matrix channels, which lead to a homogeneous deformation behavior. As the orientation deviation increases, {111}<112> slip systems begin to play a leading role during creep process. While the generation of <112> dislocations is closely related to the reaction and decomposition of <110> dislocations. Specimens on [11]-[011] boundary have coplanar double slips for {111}<110> slip systems resulting in a high initial creep rate and poor strain harding. Meanwhile, Schmid factors of {111}<112> slip systems increase rapidly with the increase of orientation deviation from [11] to [011], which lead to a significantly degradation on creep properties. While as for orientations along [11]-[001] boundary, Schmid factors increase in a relatively gentle way with the number of dominant slip systems reduced from 6 to 2. Multiplication of dislocations and the formation of <112> dislocation ribbons are impeded, resulting in a comparatively long incubation creep stage.
|
Received: 01 April 2019
|
|
Fund: Supported by National Natural Science Foundation of China(51771007、51671015);National Key Research and Development Program of China(2017YFA0700700) |
[1] | ReedR C. The Superalloys: Fundamentals and Applications [M]. Cambridge: Cambridge University Press, 2006: 121 | [2] | MatanN, CoxD C, CarterP, , et al. Creep of CMSX-4 superalloy single crystals: Effects of misorientation and temperature [J]. Acta Mater., 1999, 47: 1549 | [3] | WuX, ZhangJ H, LiuJ L, , et al. Plastic deformation inhomogeneity in a single crystal nickel-base superalloy [J]. Mater. Sci. Eng., 2002, A325: 478 | [4] | WangL N, LiuY, YuJ J, , et al. Orientation and temperature dependence of yielding and deformation behavior of a nickel-base single crystal superalloy [J]. Mater. Sci. Eng., 2009, A505: 144 | [5] | HanG M, YuJ J, SunX F, , et al. Effect of threshold stress on anisotropic creep properties of single crystal nickel-base superalloy SRR99 [J]. J. Mater. Sci. Technol., 2012, 28: 439 | [6] | MacKayR A, MaierR D. The influence of orientation on the stress rupture properties of nickel-base superalloy single crystals [J]. Metall. Trans., 1982, 13A: 1747 | [7] | LeverantG R, KearB H. The mechanism of creep in gamma prime precipitation-hardened nickel-base alloys at intermediate temperatures [J]. Metall. Mater. Trans., 1970, 1B: 491 | [8] | SassV, GlatzelU, Feller-KniepmeierM. Anisotropic creep properties of the nickel-base superalloy CMSX-4 [J]. Acta Mater., 1996, 44: 1967 | [9] | SassV, Feller-KniepmeierM. Orientation dependence of dislocation structures and deformation mechanisms in creep deformed CMSX-4 single crystals [J]. Mater. Sci. Eng., 1998, A245: 19 | [10] | RaeC M F, ReedR C. Primary creep in single crystal superalloys: Origins, mechanisms and effects [J]. Acta Mater., 2007, 55: 1067 | [11] | RaeC M F, RistM A, CoxD C, , et al. On the primary creep of CMSX-4 superalloy single crystals [J]. Metall. Mater. Trans., 2000, 31A: 2219 | [12] | KnowlesD M, ChenQ Z. Superlattice stacking fault formation and twinning during creep in γ/γ' single crystal superalloy CMSX-4 [J]. Mater. Sci. Eng., 2003, A340: 88 | [13] | JiaY X, JinT, LiuJ L, , et al. Anisotropic creep in a Ni-based single crystal superalloy [J]. Acta Metall. Sin., 2009, 45: 1364 | [13] | 贾玉贤, 金 涛, 刘金来等. 一种镍基单晶高温合金的蠕变各向异性 [J]. 金属学报, 2009, 45: 1364 | [14] | LiuJ L, JinT, SunX F, , et al. Anisotropy of stress rupture properties of a Ni base single crystal superalloy at two temperatures [J]. Mater. Sci. Eng., 2008, A479: 277 | [15] | HanG M, YuJ J, SunY L, , et al. Anisotropic stress rupture properties of the nickel-base single crystal superalloy SRR99 [J]. Mater. Sci. Eng., 2010, A527: 5383 | [16] | HopgoodA A, MartinJ W. The creep behaviour of a nickel-based single-crystal superalloy [J]. Mater. Sci. Eng., 1986, 82: 27 | [17] | KakehiK. Influence of secondary precipitates and crystallographic orientation on the strength of single crystals of a Ni-based superalloy [J]. Metall. Mater. Trans., 1999, 30A: 1249 | [18] | LinkT, Feller-KniepmeierM. Shear mechanisms of the γ' phase in single-crystal superalloys and their relation to creep [J]. Metall. Trans., 1992, 23A: 99 | [19] | DiologentF, CaronP. On the creep behavior at 1033 K of new generation single-crystal superalloys [J]. Mater. Sci. Eng., 2004, A385: 245 | [20] | HuisA J. Boom G, Bronsveld P M,, et al. Superlattice intrinsic stacking faults in γ' precipitates [J]. Scr. Metall., 1985, 19: 1123 | [21] | CondatM, DécampsB. Shearing of γ′ precipitates by single a/2<110>matrix dislocations in a γ/γ′ Ni-based superalloy [J]. Scr. Metall., 1987, 21: 607 | [22] | CourbonJ, LouchetF, IgnatM, , et al. Analysis of in situ shearing mechanisms of γ' precipitates in a nickel-based superalloy at 1120 K [J]. Phil. Mag. Lett., 1991, 63: 73 | [23] | PollockT M, FieldR D. Dislocations in Solids [M]. Chapter 63, Amsterdam: Elsevier Science & Technology Press, 2002: 549 | [24] | GunturiS S K, MacLachlanD W, KnowlesD M. Anisotropic creep in CMSX-4 in orientations distant from <001> [J]. Mater. Sci. Eng., 2000,A289: 289 | [25] | ZhangS H, WangD, ZhangJ, , et al. Orientation dependence of stress rupture properties of a Ni-based single crystal superalloy at 760 ℃ [J]. J. Mater. Sci. Technol., 2012, 28: 229 |
|
No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
|
Shared |
|
|
|
|
|
Discussed |
|
|
|
|