Abstract
93W-5.6Ni-l.4Fe tungsten heavy alloys with controlled microstructures were fabricated by mechanically alloying of elemental powders of tungsten, nickel and iron by two different process routes. One was the full mechanical alloying of blended powders with a composition of 93W-5.6Ni-l.4Fe, and the other was the partial mechanical alloying of blended powders with a composition of 30W-56Ni-14Fe followed by blending with tungsten powders to form a final composition of 93W-5.6Ni-l.4Fe. The raw powders were consolidated by die compaction followed by solid state sintering at 1300°C for 1 hour in a hydrogen atmosphere. The solid state sintered tungsten heavy alloys were subsequently liquid phase sintered at 1445∼1485°C for 4-90 min. The two-step sintered tungsten heavy alloy using mechanically alloyed 93W-5.6Ni-l.4Fe powders showed tungsten particles of about 6-15 μm much finer than those of 40 um in a conventional liquid phase sintered tungsten heavy alloy. An inhomogeneous distribution of the solid solution matrix phase was obtained in the two-step sintered tungsten heavy alloy using partially mechanically alloyed powders. The two-step sintered tungsten heavy alloy using mechanically alloyed 93W-5.6Ni-l.4Fe powders showed larger elongation of 16% than that of 1% in the solid state sintered tungsten heavy alloy due to the increase in matrix volume fraction and decrease in W/W contiguity. Dynamic torsional tests of the two-step sintered tungsten heavy alloys showed reduced shear strain at maximum shear stress than did the sintered tungsten heavy alloys using the conventional liquid phase sintering.
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References
F. V. Lenel,Powder Metallurgy: Principles and Applications, MPIF, Princeton, NJ (1980).
R. M. German, inTungsten and Tungsten Alloys-1992 (eds., A. Bose and R.J. Dowding), p. 1, MPIF, Princeton, NJ (1992).
R. M. German,Sintering Theory and Practice, John Wiley & Sons, Inc., New York, NY (1996).
L. S. Magness and T.G. Farrand,Proc. 1990 Army Science Conf., p. 149, Durham, NC (1990).
S. Cytron, inProc. Inter. Conf. on Adv. Composite Mater. (eds., T. Chandra and A.K. Dhingra), p. 973, TMS, Warren-dale, PA (1993).
D. K. Kim, S. Lee, H. J. Ryu and S. H. Hong,J. Kor. Inst. Met. & Mater. 37, 33 (1999).
K. T. Ramesh and R. S. Coates,Metall. Trans. A 23, 2625 (1992).
S. H. Hong, H. J. Ryu, E. P. Kim and W. H. Baek,Key Engineering Mater. 141-143, 453 (1998).
R. M. German, L. L. Bourguignon and B. H. Rabin,J. Met. 37, 36 (1985).
K. S. Churn and D. N. Yoon,Powder Met. 22, 175 (1979).
J. Gurland,Trans. AIME 212, 452 (1958).
A. Bose, H. Couque and J. Lankford, Jr., inTungsten and Tungsten Alloys 1992 (eds., A. Bose and R.J. Dowding), p. 291, MPIF, Princeton, NJ (1992).
A. Bose and R.M. German,Metall. Trans. A 19, 3100 (1988).
R. J. Dowding, inRecrystallization ’90 (ed., T. Chandra), p. 237, TMS, Warrendale, PA (1990).
W. E. Gurwell, inProc. 2nd Inter. Conf. on Tungsten and Refractory Metals (eds., A. Bose and R.J. Dowding), p. 65, MPIF, Princeton, NJ (1994).
M. L. Ovecoglu, B. Ozkal and C. Suryanarayana,J. Mater. Res. 11, 1673 (1996).
H. J. Ryu, S. H. Hong and W. H. Baek,J. Mater. Proc. Tech. 63, 292 (1997).
C. Zubillaga, F. Hernandez, J. J. Urcola and M. Fuentes,Acta metall. 37, 1865 (1989).
B. H. Rabin, A. Bose and R. M. German,Int. J. Powder Metall. 25, 21 (1989).
I. M. Lifshitz and V. V. Slyozov,J. Phys. Chem. Solids 19, 35(1961).
A. J. Ardell,Acta metall. 20, 61 (1972).
J. W. Noh,Ph. D. Thesis, Korea Advanced Institute of Science and Technology (1993).
G. R. Johnson, J. M. Hoegfeldt, U. S. Lindholm and A. Nagy,J. Eng. Mater. Tech. 105, 42 (1983).
R. C. Batra and Z. Peng,Int J. Impact Eng. 16, 375 (1995).
K.-M. Cho, S. Lee, S. R. Nutt and J. Duffy,Acta metall. mater. 41, 923 (1993).
M. Zhou, A. Needleman and R. J. Cliton,J. Mech. Phys. Solids 42, 423(1994).
D. K. Kim, S. Lee, H. S. Song,Metall. Mater. Trans. A 29, 1057 (1998).
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Ryu, H.J., Hong, S.H., Lee, S. et al. Microstructural control of and mechanical properties of mechanically alloyed tungsten heavy alloys. Metals and Materials 5, 185–191 (1999). https://doi.org/10.1007/BF03026051
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DOI: https://doi.org/10.1007/BF03026051