Abstract
The influence of composition on the microstructure of single crystal nickel-base superalloys was investigated. Co was replaced by Ni, and Ta was replaced by either Ni or W, according to a matrix of compositions based on MAR-M247. Substitution of Ni for Co caused an increase inγ′ solvus temperature, an increase inγ-γ′ lattice mismatch, and the precipitation of W-rich phases in the alloys with high refractory metal levels. Substitution of Ni for Ta caused large decreases inγ′ solvus temperature,γ′ volume fraction, andγ-γ′ lattice mismatch, whereas substitution of W for Ta resulted in smaller decreases in these features. For the alloys withγ′ particles that remained coherent, substitution of Ni for Co caused an increase inγ′ coarsening rate. The two alloys with the largest magnitude of lattice mismatch possessedγ′ particles which lost coherency during unstressed aging and exhibited anomalously low coarsening rates. Creep exposure at 1000 °C resulted in the formation ofγ′ lamellae oriented perpendicular to the applied stress axis in all alloys.
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J. K. Tien, T. E. Howson, G. L. Chen, and X. S. Xie:J. Metals, Oct. 1980, vol. 32, p. 12.
M. V. Nathal, R. D. Maier, and L. J. Ebert:Metall. Trans. A, 1982, vol. 13A, p. 1775.
M. V. Nathal, R.D. Maier, and L. J. Ebert:Metall. Trans. A, 1982, vol. 13A, p. 1767.
G. E. Mauer, L. A. Lackman, and J. Domingue: inProc. 4th Intl. Symp. on Superalloys, J. K. Tien, S. T. Wlodek, H. Morrow, M. Gell, and G. E. Mauer, eds., ASM, Metals Park, OH, 1980, p. 43.
R. N. Jarrett and J. K. Tien:Metall. Trans. A, 1982, vol. 13A, p. 1021.
M. V. Nathal and L.J. Ebert:Metall. Trans. A, 1985, vol. 16A, p. 1863.
T. E. Strangman, G. S. Hoppin, C. M. Phipps, K. Harris, and R. E. Schwer: inProc. 4th Intl. Symp. on Superalloys, J. K. Tien, S. T. Wlodek, H. Morrow, M. Gell, and G. E. Mauer, eds., ASM, Metals Park, OH, 1980, p. 215.
M. J. Donachie and O. H. Kriege:J. Mat., 1972, vol. 7, p. 269.
P. K. Rastogi and A.J. Ardell:Acta Metall., 1971, vol. 19, p. 321.
E. H. VanDerMolen, J. M. Oblak, and O. H. Kriege:Metall. Trans., 1971, vol. 2, p. 1627.
R. L. Dreshfield: NASA TMX-73663, 1977, National Technical Information Services, Springfield, VA 22161.
M. V. Nathal and L.J. Ebert:Metall. Trans. A, 1985, vol. 16A, p. 427.
F. C. Hull:Metal Progress, 1969, vol. 96, p. 139.
W. T. Loomis, J. W. Freeman, and D. L. Sponseller:Metall. Trans., 1972, vol. 3, p. 989.
A. J. Ardell and R. B. Nicholson:J. Phys. Chem. Solids, 1966, vol. 27, p. 1793.
C. K. L. Davies, P. Nash, and R. N. Stevens:J. Mat. Sci., 1980, vol. 15, p. 1521.
O. H. Kriege and J. M. Barris:Trans. ASM, 1962, vol. 62, p. 195.
P. Caron and T. Khan:Mat. Sci. Eng., 1983, vol. 61, p. 173.
H. C. Nguyen, B. J. Pletka, and R. W. Heckel: inHigh Temperature Alloys: Theory and Design, J. O. Stiegler, ed., AIME, Warrendale, PA, 1984, p. 381.
E. Aigeltinger and M. Kersker:Metals Forum, 1981, vol. 4, p. 112.
W. B. Pearson:Handbook of Lattice Spacings and Structures of Metals, Pergamon Press, New York, NY, 1959, vols. 1, 2, p. 776.
M. V. Nathal, R. A. MacKay, and R. G. Garlick:Mat. Sci. Eng., in press.
D. A. Grose and G. S. Ansell:Metall. Trans. A, 1981, vol. 12A, p. 1631.
T. Khan, P. Caron, and C. Duret: inSuperalloys 1984: Proc. Fifth Int. Symp. on Superalloys, M. Gell, C. S. Kortovich, R.H. Bricknell, W. B. Kent, and J. F. Radavich, eds., AIME, Warrendale, PA, 1984, p. 145.
A. Fredholm and J. L. Strudel: inSuperalloys 1984: Proc. Fifth Int. Symp. on Superalloys, M. Gell, C. S. Kortovich, R. H. Bricknel, W. B. Kent, and J. F. Radavich, eds., AIME, Warrendale, PA, 1984, p. 211.
R. B. Nicholson: inInterfaces Conference, R. C. Gifkins, ed., Aust. Inst. Metals, Melbourne, Australia, 1969, p. 139.
P. K. Footner and B. P. Richards:J. Mat. Sci., 1982, vol. 17, p. 2141.
J. W. Martin and F. J. Humphreys:Scripta Metall., 1974, vol. 8, p. 679.
A. Lasalmonie and J. L. Strudel:Phil. Mag., 1975, vol. 32, p. 937.
A. J. Porter, R. A. Ricks, and R. C. Ecob:J. Mat. Sci., 1983, vol. 18, p. 1895.
H. I. Aaronson: inDecomposition of Austenite by Diffusional Processes, V. F. Zackay and H. I. Aaronson, eds., Interscience Publishers, New York, NY, 1960, p. 387.
R. F Decker: inSteel Strengthening Mechanisms Symposium, Climax Molybdenum Co., Greenwich, CT, 1969, p. 147.
R. G. Davies and T. L. Johnson: inOrdered Alloys: Structural Applications and Physical Metallurgy, B. H. Kear, C. T. Sims, N. S. Stoloff, and J. H. Westbrook, eds., Claitor’s Publishing Division, Baton Rouge, LA, 1970, p. 447.
B. Bergman:Scand. J. Metall., 1975, vol. 4, p. 97.
T. B. Gibbons and B. E. Hopkins:Met. Sci. J., 1971, vol. 5, p. 233.
V. Biss and D. L. Sponseller.Metall. Trans., 1973, vol. 4, p. 1953.
D. D. Pearson, B. H. Kear, and F. D. Lemkey: inCreep and Fracture of Engineering Materials and Structures, B. Wilshire and D. R. J. Owen, eds., Pineridge Press, Swansea, UK, 1981, p. 213.
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Nathal, M.V., Ebert, L.J. The influence of cobalt, tantalum, and tungsten on the microstructure of single crystal nickel-base superalloys. Metall Trans A 16, 1849–1862 (1985). https://doi.org/10.1007/BF02670372
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DOI: https://doi.org/10.1007/BF02670372