In the present study, a novel strengthening mechanism that does not impair the plasticity has been ascertained in a directionally solidified nickel-based superalloy (DS alloy) during monotonic and cyclic deformations. The alloy exhibited excellent mechanical properties at 750°C. Sub-structural examinations revealed that the activation of the stacking fault-induced micro-twinning mechanism is responsible for the improved fatigue performance at 750°C. This work may lead us to design advanced nickel-based superalloys having good synergy of strength and plasticity for turbine blade applications.
HarrisKEricksonGLSchwerRE.MAR M 247 derivations - CM 247 LC DS alloy CMSX single crystal alloys properties & performance. Superalloys. 1984;1984:221–230.
2.
NathalMVMackayRAGarlickRG.Temperature dependence of γ-γ' lattice mismatch in nickel-base superalloys. Mater Sci Eng. 1985;75:195–205.
3.
KimISChoiBGHongHUAnomalous deformation behavior and twin formation of Ni-base superalloys at the intermediate temperatures. Mater Sci Eng A. 2011;528(24):7149–7155.
4.
RaiR.K., SahuJ.K., PauloseN., and FernandoC.. Low cycle fatigue behavior of a directionally solidified nickel-based superalloy: mechanistic and microstructural aspect. Metall Mater Trans., 2020, vol. 51, pp. 2752–2765.
5.
GopinathKGogiaAKKamatSVDynamic strain ageing in Ni-base superalloy 720Li. Acta Mater. 2009;57(4):1243–1253.
6.
RaiRKSahuJKDasSKCyclic plastic deformation behaviour of a directionally solidified nickel base superalloy at 850°C: damage micromechanisms. Mater Charact. 2018;141:120–128.
7.
RaiRKSahuJKJenaPSMMicromechanism of high-temperature tensile deformation behavior of a directionally solidified nickel base superalloy. J Mater Eng Perform. 2018;27(2):659–665.
8.
GuimierAStrudelJL.ASM. (CA); 1970. p. 56–59.
9.
KearBHOblakJMGiameiAF.Second international conference on the strength of metals and alloys. (ASM); 1970. p. 1155–1159.
10.
KolbeM.The high temperature decrease of the critical resolved shear stress in nickel-base superalloys. Mater Sci Eng A. 2001;319–321:383–387.
11.
ViswanathanGBSarosiPMHenryMF.Investigation of creep deformation mechanisms at intermediate temperatures in René 88. Acta Mater. 2005;53:3041–3057.
12.
KnowlesDMGunturiS.The role of {112}{111} slip in the asymmetric nature of creep of single crystal superalloy CMSX-4. Mater Sci Eng A. 2002;328:223–237.
13.
KnowlesDMChenQZ.Superlattice stacking fault formation and twinning during creep in γ/γ′ single crystal superalloy CMSX-4. Mater Sci Eng A. 2003;340:88–102.
14.
LuLChenXHuangXRevealing the maximum strength in nanotwinned copper. Science. 2009;323:607–610.
15.
ZhangYTaoNRLuK.Effects of stacking fault energy, strain rate and temperature on microstructure and strength of nanostructured Cu–Al alloys subjected to plastic deformation. Acta Mater. 2011;59:6048–6058.
16.
LiYSZhangYTaoNREffect of thermal annealing on mechanical properties of a nanostructured copper prepared by means of dynamic plastic deformation. Scripta Mater. 2008;59:475–478.
