Aiming to improve γ′ volume fraction through alloying elements and heat treatments, the influence of the combined effect of 2 Ti and 2 Ta addition (at%) to a nominal Co–12Al–10W at.% Co-based superalloy, and the heat treatments parameters have been investigated. The Co-based alloys were manufactured by PM using mechanical alloying for powder processing, and a field-assisted sintering technique to consolidate the material. The specific study of solution temperatures and ageing times to promote the γ/γ′ dual-phase was carried out through a complete microstructural analysis and micro and nano hardness measurements. The composition of the γ (fcc)-matrix and γ′ (L12)-precipitates, the nanoscale properties including γ′ volume fraction and γ/γ′ misfit were measured as a function of increasing solution and ageing time. In the end, Ti and Ta addition to the Co–12A–10W alloy increases γ’ volume fraction and thermal stability for long ageing time detecting slow coarsening.
ReedRC.The superalloys: fundamentals and applications. Cambridge: Cambridge University Press; 2006.
2.
SimsCT, StoloffNS, HagelWC.Superalloys II: high-temperature materials for aerospace and Industrial power. New York: John Wiley & Sons, co; 1987.
3.
ZhangQ, ChangY, GuL, Study of microstructure of nickel-based superalloys at high temperatures. Scr Mater. 2016;126:55–57. doi:10.1016/j.scriptamat.2016.08.013.
LeeCS.Precipitation-hardening characteristics of ternary cobalt – aluminum – X alloys. Ph.D. Engineering Metallurgy. The University of Arizona; 1971.
6.
PollockTM, DibbernJ, TsunekaneM, New co-based γ-γ′ high-temperature alloys. JOM. 2010;62(1):58–63.
7.
XueF, ZhouHJ, DingXF, Improved high temperature γ’ stability of Co-Al-W-base alloys containing Ti and Ta. Mater Lett. 2013;112:215–218. doi:10.1016/j.matlet.2013.09.023.
8.
NeumeierS, FreundLP, GökenM.Novel wrought γ/γ′ cobalt base superalloys with high strength and improved oxidation resistance. Scr Mater. 2015;109:104–107. doi:10.1016/j.scriptamat.2015.07.030.
9.
YanHY, VorontsovVA, CoakleyJ, Quaternary alloying effects and the prospects for a new generation of Co-base superalloys. Superalloys. 2012;2012:705–714. doi:10.1002/9781118516430.ch78.
10.
BauerA, NeumeierS, PyczakF, Microstructure and creep strength of different γ/γ′- strengthened Co-base superalloy variants. Scr Mater. 2010;63(12):1197–1200. doi:10.1016/j.scriptamat.2010.08.036.
XueF, WangM, FengQ.Alloying effects on heat-treated microstructure in Co-Al-W-base superalloys at 1300°C and 900°C. Superalloys. 2012;2012:813–821. doi:10.1002/9781118516430.ch90.
13.
SuzukiA, PollockTM.High-temperature strength and deformation of c/c 0 two-phase Co-Al-W-base alloys. Acta Mater. 2008;56(6):1288–1297. doi:10.1016/j.actamat.2007.11.014.
14.
ChungDW, ToininJP, LassEA, Effects of Cr on the properties of multicomponent cobalt-based superalloys with ultra high γ′ volume fraction. J Alloys Compd. 2020;832:154790. doi:10.1016/j.jallcom.2020.154790.
15.
LassEA, SauzaDJ, DunandDC, Multicomponent g’-strengthened Co-based superalloys with increased solvus temperatures and reduced mass densities. Acta Mater. 2018;147:284–295. doi:10.1016/j.actamat.2018.01.034.
16.
LassEA.Application of computational thermodynamics to the design of a Co-Ni-based γ′-strengthened superalloy. Metall Mater Trans A. 2017;48(5):2443–2459. doi:10.1007/s11661-017-4040-y.
17.
YoonKE, NoebeRD, SeidmanDN.Effects of rhenium addition on the temporal evolution of the nanostructure and chemistry of a model Ni-Cr-Al superalloy. I: experimental observations. Acta Mater. 2007;55:1145–1157. doi:10.1016/j.actamat.2006.08.027.
18.
ZhangL, UkaiS, HoshinoT, Y2O3 evolution and dispersion refinement in Co-base ODS alloys. Acta Mater. 2009;57(12):3671–3682. doi:10.1016/j.actamat.2009.04.033.
19.
ZhangL, Microstructural formation in novel Co-base ODS alloys produced by mechanical alloying. Adv Mater Res. 2012;415–417:1136–1139. doi:10.4028/www.scientific.net/AMR.415-417.1136.
20.
ZhangL, QuX, HeX, Hot deformation behavior of Co-base ODS alloys. J Alloys Compd. 2012;512(1):39–46. doi:10.1016/j.jallcom.2011.08.097.
21.
ZhangL, QuX, QinM, Microstructure and mechanical properties of γ′ strengthened Co-Ni-Al-W-base ODS alloys. Mater Chem Phys. 2012;136(2–3):371–378. doi:10.1016/j.matchemphys.2012.06.055.
22.
ZhangL, Microstructural characterization of co-based ODS alloys. J Mater Eng Perform. 2012;21(11):2487–2494. doi:10.1007/s11665-012-0206-3.
23.
CasasR, GálvezF, CamposM.Microstructural development of powder metallurgy cobalt-based superalloys processed by field assisted sintering techniques (FAST). Mater Sci Eng A. 2018;724; doi:10.1016/j.msea.2018.04.004.
24.
Cartón-CorderoM, SrinivasaraoB, CamposM, On the role of processing parameters in sintered new Co-based (W,Al) alloys. J Alloys Compd. 2016;674:406–412. doi:10.1016/j.jallcom.2016.03.077.
25.
Cartón-CorderoM, Microstructure and compression strength of Co-based superalloys hardened by γ′ and carbide precipitation. Mater Sci Eng A. 2018;734(May):437–444. doi:10.1016/j.msea.2018.08.007.
26.
IshidaK.Intermetallic compounds in co-based alloys-phase stability and application to superalloys. Mater Res Soc. 2009;1128.
27.
PovstugarI, Elemental partitioning and mechanical properties of Ti- and Ta-containing Co-Al-W-base superalloys studied by atom probe tomography and nanoindentation. Acta Mater. 2014;78:78–85. doi:10.1016/j.actamat.2014.06.020.
28.
CuiYF, ZhangX, XuGL, Thermodynamic assessment of Co-Al-W system and solidification of Co-enriched ternary alloys. J Mater Sci. 2011;46(8):2611–2621. doi:10.1007/s10853-010-5115-y.
29.
Muñoz-MorenoR, Ruiz-NavasEM, SrinivasaraoB, Microstructural development and mechanical properties of PM Ti-45Al-2Nb-2Mn-0.8vol.%TiB2 processed by field assisted hot pressing. J Mater Sci Technol. 2014;30(11):1145–1154. doi:10.1016/j.jmst.2014.08.008.
30.
PollockTM, TinS.Nickel-based superalloys for advanced turbine engines: chemistry, microstructure and properties. J Propuls Power. 2006;22(2):361–374.
31.
OliverWC, PharrGM.An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments. J Mater Res. Jun. 1992;7(6):1564–1583. doi:10.1557/JMR.1992.1564.
32.
ShinagawaK, Phase equilibria and microstructure on γ′ phase in Co-Ni-Al-W system. Mater Trans. 2008;49(6):1474–1479. doi:10.2320/matertrans.MER2008073.
33.
LiuC, SunY, WenM, Effect of Cr addition on microstructure and welding solidification cracking susceptibility of Co-Al-W based superalloys. J Manuf Process. 2020;56(March):820–829. doi:10.1016/j.jmapro.2020.03.049.
34.
KobayashiS, TsukamotoY, TakasugiT.Phase equilibria in the Co-rich Co-Al-W-Ti quaternary system. Intermetallics. 2011;19(12):1908–1912. doi:10.1016/j.intermet.2011.08.004.
35.
LassEA.The effects of Fe and Si on the phase equilibria in a γ′-strengthened Co–Al–W-based superalloy. J Alloys Compd. 2020;825; doi:10.1016/j.jallcom.2020.154158.
36.
LiuX, KongH, LuY, Phase-field simulation on microstructure evolution of D019 phase in γ/γ′ structure of Co–Al–W superalloys. Prog Nat Sci Mater Int. 2020;30(3):382–392. doi:10.1016/j.pnsc.2020.05.004.
37.
MughrabiH, TetzlaffU.Microstructure and high-temperature strength of monocrystalline nickel-base superalloys. Adv Eng Mater. 2000;2(6):319–326. doi:10.1002/1527-2648(200006)2:6<319::AID-ADEM319>3.0.CO;2-S.
38.
PollockTM, FieldRD.Chapter 63 Dislocations and high-temperature plastic deformation of superalloy single crystals. Disloc Solids. Jan. 2002;11(C):547–618. doi:10.1016/S1572-4859(02)80014-6.
39.
ZhangJX, WangJC, HaradaH, The effect of lattice misfit on the dislocation motion in superalloys during high-temperature low-stress creep. Acta Mater. 2005;53:4623–4633. doi:10.1016/j.actamat.2005.06.013.
40.
TanakaK, OoshimaM, TsunoN, Creep deformation of single crystals of new Co–Al–W-based alloys with fcc/L12 two-phase microstructures. Philos Mag. Nov. 2012;92(32):4011–4027. doi:10.1080/14786435.2012.700416.
41.
PyczakF, Plastic deformation mechanisms in a crept L1 2 hardened Co-base superalloy. Mater Sci Eng A. 2013;571:13–18. doi:10.1016/j.msea.2013.02.007.
42.
MughrabiH.The importance of sign and magnitude of γ/γ′ lattice misfit in superalloys-with special reference to the new γ′-hardened cobalt-base superalloys. Acta Mater. 2014;81:21–29. doi:10.1016/j.actamat.2014.08.005.
43.
EpishinAI, LinkT, FedelichB, Hot isostatic pressing of single-crystal nickel-base superalloys: mechanism of pore closure and effect on mechanical properties. MATEC Web Conf. 2014;14; doi:10.1051/matecconf/20141408003.
44.
CollinsDM, Lattice misfit during ageing of a polycrystalline nickel-base superalloy. Acta Mater. 2013;61(20):7791–7804. doi:10.1016/j.actamat.2013.09.018.
45.
OoshimaM, TanakaK, OkamotoNL, Effects of quaternary alloying elements on the γ′ solvus temperature of Co-Al-W based alloys with fcc/L12 two-phase microstructures. J Alloys Compd. 2010;508(1):71–78. doi:10.1016/j.jallcom.2010.08.050.
46.
GuanY, LiuY, MaZ, Investigation on γ′ stability in CoNi-based superalloys during long-term aging at 900°C. J Alloys Compd. 2020;842:1–10. doi:10.1016/j.jallcom.2020.155891.
47.
LiY, Thermal stability of γ′ phase in long-term aged Co-Al-W alloys. J Alloys Compd. 2017;729(September):266–276. doi:10.1016/j.jallcom.2017.09.157.
48.
WagnerC, ElektrochemZ.Theory of precipitate change by redissolution (Ostwald Reifung). Z Elektrochem. 1961;65:581–591.
49.
LifshitzIM, SlyozovVV.The kinetics of precipitation from supersaturated solid solutions. J Phys Chem Solids. Apr. 1961;19(1–2):35–50. doi:10.1016/0022-3697(61)90054-3.
50.
SauzaDJ, BocchiniPJ, DunandDC, Influence of ruthenium on microstructural evolution in a model Co-Al-W superalloy. Acta Mater. 2016;117:135–145. doi:10.1016/j.actamat.2016.07.014.
51.
MeherS, NagS, TileyJ, Coarsening kinetics of γ′ precipitates in cobalt-base alloys. Acta Mater. 2013;61(11):4266–4276. doi:10.1016/j.actamat.2013.03.052.
52.
TitusMS, SuzukiA, PollockTM.High temperature creep of new L12-containing cobalt-base superalloys. Superalloys 2012: 12th Int Sym on Superalloys. 2012: 823–832.
53.
LassEA, SauzaDJ, DunandDC, Multicomponent γ′-strengthened co-based superalloys with increased solvus temperatures and reduced mass densities. Acta Mater. Apr. 2018;147:284–295. doi:10.1016/j.actamat.2018.01.034.
54.
LongFR, Microstructure and creep performance of a multicomponent co-based L12–ordered intermetallic alloy. Acta Mater. 2020;196:396–408. doi:10.1016/j.actamat.2020.06.050.
