Browse > Article
http://dx.doi.org/10.7777/jkfs.2020.40.4.118

The Effect of Temperature on Tensile Properties in Conventionally Cast Ni-based Superalloy CM247LC  

Choi, Baig-Gyu (High Temperature Materials Center, Korea Institute of Materials Science)
Kim, In Soo (High Temperature Materials Center, Korea Institute of Materials Science)
Do, Jeonghyeon (High Temperature Materials Center, Korea Institute of Materials Science)
Jung, Joong Eun (High Temperature Materials Center, Korea Institute of Materials Science)
Seok, Woo-Young (High Temperature Materials Center, Korea Institute of Materials Science)
Lee, Yu-Hwa (High Temperature Materials Center, Korea Institute of Materials Science)
Publication Information
Journal of Korea Foundry Society / v.40, no.4, 2020 , pp. 118-127 More about this Journal
Abstract
Microstructural evolution during a heat treatment and high-temperature tensile properties have been investigated in conventionally cast CM247LC. In as-cast specimens, MC carbides with high amounts of Ta, Ti, Hf, and W were found to exist in the interdendritic regions, and γ' was observed in the form of cubes and octocubes prior to decomposition into cubes. In the heat-treated condition, some portion of eutectic γ-γ' remained, and uniform cubic γ' was observed in both interdendritic regions and dendrite core. Three types of carbides with different stoichiometries and compositions were found at the grain boundaries. MC carbides with high Hf contents were observed in the vicinity of eutectic γ-γ'. The highest tensile strength value was found at 750℃, whereas the greatest ductility appeared at 649℃. The effect of the temperature on the tensile properties was closely related to the dislocation structure. With increase in the test temperature, the density of dislocations inside γ' decreased, whereas that in the γ matrix increased. Stacking faults generated in γ' at 750℃ had a strengthening effect, whereas thermally activated dislocation motion at a high temperature was considered to have the opposite effect.
Keywords
Ni-based superalloy; CM247LC; Tensile property; Dislocation;
Citations & Related Records
연도 인용수 순위
  • Reference
1 King D, Inderwildi O and Carey C, Aviation and the Environment (Paris airshow special edition), "Advanced aerospace materials: past, present and future", 3 (2009) 22-27.
2 Reed RC, The Superalloys - Fundamentals and Applications, Cambridge University Press, Cambridge (2006) 18-25, 65-73.
3 Kaufman M, Superalloys 1984 (ed. M. Gell, et al.), "Propeties of Cast Mar-M247 for Turbine Blisk Applications", Met. Soc. AIME, Warrendale, PA (1984) 43-52.
4 Harris K, Erickson GL and Schwer RE, Superalloys 1984 (ed. M. Gell, et al.), "Mar-M247 derivations - CM 247 LC DS alloy CMSX single crystal alloys properties & performance", Met. Soc. AIME, Warrendale, PA (1984) 221-230.
5 Erickson GL, Harris K and Schwer RE, ASME 1985 Interational Gas Turbine Conference and Exhibit, "Directionally solidified DS CM 247 LC - optimized mechanical properties resulting from extensive ${\gamma}$' solutioning", Paper No. 85-GT-107, ASME, Huston, Texas (1985) 1-10.
6 Huang HE and Koo CH, Mater. Trans. Japan, "Characteristics and mechanical properties of polycrystalline CM247LC superalloy castings", 45 (2004) 562-568.   DOI
7 Kim IS, Choi BG, Jeong JE, Do J, Seok WY, Lee YH and Jeong IY, Mater. Charact., "Effect of microstructural evolution by heat treatment on creep behaviors of a nickel-based superalloy CM247LC", 165 (2020) article 110378 (accepted).
8 Choi BG, Kim IS, Kim DH and Jo CY, J. Kor. Inst. Met. & Mater., "Microstructural evolution and degradation of tensile properties during thermal exposure in Ni-base superalloy CM247LC", 43 (2005) 867-873.
9 Khan T, Caron P, Fournier D and Harris K, Steel & Special Alloys for aerospace, Paris Airshow, "Single crystal superalloys for turbine blades: characterization and optimization CMSX-2 Alloy", Le Bourget (1985) 1-13.
10 Ross EW, Sims CT. Superalloys II (ed. Sims CT et al.), "Nickel-base alloys", NewYork, JohnWiley&Sons (1987) 97-133.
11 Kim DH, Choi BG and Jo CY, J. Kor. Inst. Met. & Mater. "Creep properties and carbide reaction of a Ni-base superlloy Mar-M247", 43 (2005) 841-846 .
12 Collins HE, Superalloy Proceedings of the First International Conference, "Relative sability of carbide and intermetallic phases in nickel-base superalloys", Metallurgical Society of AIME, New York (1968) 171-198.
13 Link T, and Feller-Kniepmeier M, Metall. Trans. A, "Shear mechanisms of the ${\gamma} phase in single crystal superalloys and their relation to creep", 23 (1992) 99-105.   DOI
14 Wang HP, Sluiter M and Kawazoe Y, Mater. Trans. JIM, "Prediction of the effect of Ti on the (111) and (100) antiphase boundary energy in $Ni_3Al$", 40 (1999) 1301-1305.   DOI
15 Wang-Koh YM, Mater. Sci. Tech., "Understanding the yield behaviour of L12-ordered alloys", 33 (2017) 934-943.   DOI
16 Milligan WW and Antolovich SD, Metall. Trans. A, "The mechanisms and temperature dependence of superlattice stacking fault formation in the single-crystal superalloy PWA 1480", 22 (1991) 2309-2318.   DOI
17 Wen YF, Sun J and Huang J, Trans. Nonferrous Met. Soc., "First-principles study of stacking fault energies in $Ni_3Al$ intermetallic alloys", 22 (2012) 661-664.   DOI
18 Remy L and Pineau A, Mater. Sci. Eng., "Temperature dependence of stacking fault energy in closed-packed metals and alloys" 36 (1978) 47-63.   DOI
19 Tian S, Qian B, Su Y, Yu H and Yu X, Mater. Sci. Forum, "Influence of stacking fault energy on creep mechanism of a single crystal nickel-based superalloy containing Re", 706-709 (2012) 2474-2479.
20 Kruml T, Viguier B, Bonneville J and Martin JL, Mater. Sci. Eng. A "Temperature dependence of dislocation microstructure in $Ni_3$(Al,Hf)", 234-236 (1997) 755-757.   DOI
21 Choi BG, Kim IS, Hong HU, Do J, Jung JE and Jo CY, Met. Mater. Int., "Effect of Ti content on creep properties of Nibase single crystal superalloys", 23 (2017) 877-883.   DOI