The Effect of Sintering Conditions on the Microstructural Parameters of Particle Composites

Abstract:

Tungsten heavy alloys are particle composites; they occupy a unique position in materials because of their combination of high density, strength and ductility. The main focus of this study was to examine the effect of sintering conditions (temperature and time) on the microstructural parameters of tungsten heavy alloys. Alloys composed of 88%, 93% and 95% wt. of tungsten and either Ni: Fe (in the ratio of 7:3) or Ni: Co (in the ratio of 7:3) were consolidated into green compacts. Samples of each of the six resulting alloys were sintered in hydrogen atmosphere at different temperatures for different sintering holding times. The microstructural parameters of both types were found to be roughly similar at each temperature and holding time. At higher sintering temperature and longer sintering holding times there was a matrix gradient and the formation of FeNi intermetallic phases at tungsten matrix interfaces. The microstructural parameters showed that the W-Ni-Co alloys may have some advantage as a result of their small tungsten grains and the lower contiguity.

• Periodical: Advanced Materials Research (Volumes 129-131)
• Pages: 438-444
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.129-131.438
• Online since: August 2010
• Authors: S.H. Islam, M.A. Al-Eshaikh
• Keywords: Liquid Phase Sintering (LPS), Microstructural Parameter, Tungsten Heavy Alloy

References

[1] S.H. Islam, , F. Akhtar, S.J. Askari, X.H. Qu, Int. J. Refract. Met. Hard Mat. Volume 25, Issues 5-6, September-November 2007, Pages 380-3852.

[2] S.H. Islam, X.H. Qu, F. Akhtar, P. Z Feng, X.B. He, Mater Sci Forum 534-536 (2007) 561.

[3] S.H. Islam, X.H. Qu, X.B. He, Investigation of composition and microstructure effect on fracture behavior of tungsten heavy alloys, Powd Metall, 50(1) (2007) 11.

[4] A. Sunwooe, S. Groves, D. Goto, H. Hopkins, Mater. Lett. 60 (2006) 321.

[5] A. Upadhaya, Mater. Chem. Phys. 67 (2001) 101.

[6] R Gero, L Borukhin, I Pikus, , Mater. Sci. Eng. A 302 (2001) 162.

[7] B.H. Rabin, R.M. German, Metall. Trans. A, Phys. Metall. Mater. Sci. 19 A (1988) 1523.

[8] R.M. German, in: A. Bose, R.J. Dowding (Eds. ), Proc. Int. Conf. on Tungsten and Tungsten Alloys, MPIF, Princeton, New Jersey, 1992, 3.

[9] Gurwell W E, in Progress in Powder Metallurgy, Vol. 42, edited by E A Carlson and G. Gaines, Metal Powder Industries Federation, Princeton, N.J. (1986) 569.

[10] M.H. Hong, E.P. Kim, W.H. Baek, I.H. Moon, Metall. Trans. A, Phys. Metall. Mater. Sci. 30 A (1999) 627.

[11] R.M. German, Liquid Phase Sintering, Plenum Press, New York, NY (1985) 1.

[12] R.M. German, Sintering Theory and Practice, John Wiley and Sons, Inc., New Yor, (1996).

[13] JCPDS, Powder Diffraction File Search Manual, Hanawalt Method, Inorganic, , International Center for Diffraction Data, Swarthmore, PA, (1990).

[14] B.C. Muddle, Metall. Trans. A 15A (1984) 1089.

[15] R, M. German, J. E. Hanafee and S. L. Digiallonardo, Metall. Trans. A 15A (1984) 121.

[16] J. B. Posthill, M. C. Hogwood and D. V. Edmonds, Powder Met. 29 (1986) 45.

[17] A. F. Guillermet and L. Ostlund, Metall. Teans. A 17A (1986) 1809.

[18] R. V. Minakova, N. A. Strochak, P. A. Verkhovodov, L. G. BazhenovaA and V.L. Poltoraktskaya, Soviet Powder Met. Metal Cerarn. 19 (1980) 842.

[19] T. Antonsson, L. Ekbom, Powd Metall., 2001, 44, 325.