Segregation assisted microtwinning during creep of a polycrystalline L12-hardened Co-base superalloy
Source abstract
Abstract
Abstract A polycrystalline L12-hardened Co-base superalloy was creep deformed at 750 °C. The investigation of the deformed microstructure in the transmission electron microscope revealed microtwinning to be the prevailing deformation mechanism. The detected twins spanned the entire grain and cut through both, γ and γ′. Detailed high-resolution transmission electron microscopy investigations indicated that twin growth takes place by the slip of single a/6 〈112〉 partial dislocations along the twin boundary. Further analysis of the twin boundaries in the γ′ phase revealed segregation of elements known to decrease the stacking fault energy and a local depletion of γ′ forming elements. We propose that this segregation behavior enables subsequent a/6〈112〉 dislocations to easily slip along the twin boundary and further thicken the twins in the process.
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Research context
OpenAlex topics: High Temperature Alloys and Creep · Microstructure and mechanical properties · Intermetallics and Advanced Alloy Properties
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (44)
Show source-provided references
1. Trends in high-temperature alloys
2. Cobalt-base high-temperature alloys10.1126/science.1121738 ↗
3. Flow stress anomalies in γ/γ′ two-phase Co–Al–W-base alloys10.1016/j.scriptamat.2006.10.039 ↗
4. High-temperature strength and deformation of γ/γ′ two-phase Co–Al–W-base alloys10.1016/j.actamat.2007.11.014 ↗
5. Creep strength and microstructure of polycrystalline γ′-strengthened cobalt-base superalloys
6. Creep and directional coarsening in single crystals of new γ–γ′ cobalt-base alloys10.1016/j.scriptamat.2012.01.008 ↗
7. Effect of alloying on the oxidation behaviour of Co–Al–W superalloys10.1016/j.corsci.2014.03.002 ↗
8. Phase equilibria and microstructure in γ′ phase in Co-Ni-Al-W system10.2320/matertrans.MER2008073 ↗
9. Microstructure and creep strength of different γ/γ’-strengthened Co-base superalloy variants10.1016/j.scriptamat.2010.08.036 ↗
10. Creep-induced planar defects in L12-containing Co- and CoNi-base single-crystal superalloys10.1016/j.actamat.2014.08.033 ↗
11. Creep deformation-induced antiphase boundaries in L12-containing single-crystal cobalt-base superalloys10.1016/j.actamat.2014.04.037 ↗
12. Novel wrought γ/γ′ cobalt base superalloys with high strength and improved oxidation resistance10.1016/j.scriptamat.2015.07.030 ↗
13. A new polycrystalline Co-Ni superalloy10.1007/s11837-014-1175-9 ↗
14. High-temperature γ(FCC)/γ′(L12) Co-Al-W based superalloys10.1051/matecconf/20141418003 ↗
15. On the precipitation of delta phase in ALLVAC® 718Plus10.1080/14786435.2013.878052 ↗
16. Monograph · 1960
17. Characterization of plastic deformation induced by shot-peening in a Ni-Base superalloy10.1007/s11837-014-1184-8 ↗
18. The growth of γ′ precipitates in nickel-base superalloys10.1016/0001-6160(83)90062-7 ↗
19. Mechanical properties of Ni3Al and Nickel-base alloys with high volume fraction of γ′
20. Dislocations in a Ni-based superalloy during low temperature creep10.1051/matecconf/20141401006 ↗
21. Temperature dependence of deformation behavior in a Co–Al–W-base single crystal superalloy10.1016/j.msea.2014.09.074 ↗
22. Primary creep in single crystal superalloys: origins, mechanisms and effects10.1016/j.actamat.2006.09.026 ↗
23. Investigation of creep deformation mechanisms at intermediate temperatures in René 88 DT10.1016/j.actamat.2005.03.017 ↗
24. Direct observation of an extended complex stacking fault in the γ′ phase of a Ni-base superalloy10.1016/j.scriptamat.2006.06.019 ↗
25. Plastic deformation mechanisms in a crept L12 hardened Co-base superalloy10.1016/j.msea.2013.02.007 ↗
26. Mechanism of dislocation shearing of γ′ in fine precipitate strengthened superalloy10.1179/026708301101509818 ↗
27. On the shearing mechanism of γ′ precipitates by a single (a/6)〈112〉 Shockley partial in Ni-based superalloys10.1080/14786430310001621472 ↗
28. Superlattice stacking fault formation and twinning during creep in γ/γ′ single crystal superalloy CMSX-410.1016/S0921-5093(02)00172-7 ↗
29. Microtwinning and other shearing mechanisms at intermediate temperatures in Ni-based superalloys10.1016/j.pmatsci.2009.03.010 ↗
30. Mechanisms of creep deformation in polycrystalline Ni-base disk superalloys10.1016/j.msea.2006.08.148 ↗
31. Microtwinning during intermediate temperature creep of polycrystalline Ni-based superalloys: mechanisms and modelling10.1080/14786430600767750 ↗
32. Creep deformation mechanism mapping in nickel base disk superalloys10.1080/09603409.2016.1180858 ↗
33. The high temperature decrease of the critical resolved shear stress in nickel-base superalloys10.1016/S0921-5093(01)00944-3 ↗
34. The influence of alloying, temperature, and related effects on the stacking fault energy10.1007/BF03038370 ↗
35. Direct estimation of stacking fault energy by thermodynamic analysis10.1002/pssa.2210360233 ↗
36. A first-principles study of the effect of Ta on the superlattice intrinsic stacking fault energy of L12-Co3(Al,W)10.1016/j.intermet.2012.04.020 ↗
37. Plastic deformation of polycrystals of Co3(Al,W) with the L12 structure10.1080/14786435.2011.586158 ↗
38. Alloying effects in the γ′ phase of Co-based superalloys10.7449/2012/Superalloys_2012_685_693 ↗
39. L12 -strengthened cobalt-base superalloys10.1146/annurev-matsci-070214-021043 ↗
40. Segregation at stacking faults within the γ′ phase of two Ni-base superalloys following intermediate temperature creep10.1016/j.scriptamat.2014.06.032 ↗
41. Segregation and η phase formation along stacking faults during creep at intermediate temperatures in a Ni-based superalloy10.1016/j.actamat.2015.08.053 ↗
42. High resolution energy dispersive spectroscopy mapping of planar defects in L12-containing Co-base superalloys10.1016/j.actamat.2015.01.050 ↗
43. Planar defect formation in the γ′ phase during high temperature creep in single crystal CoNi-base superalloys10.1016/j.actamat.2016.03.077 ↗
44. Diffusion of solutes in fcc Cobalt investigated by diffusion couples and first principles kinetic Monte Carlo10.1016/j.actamat.2016.01.028 ↗