Conclusions
The kinetics of tungsten grain growth during the LPS of a very finely divided W-20% Cu mixture and of densification of the composite in the middle stage of LPS is determined by a process of transport of the refractory component through the liquid phase. Under conditions of full separation of the refractory grains by the second phase the character of the variation of the viscosity and rate of local nonuniform deformation of the two-phase material indicates that the densification of such a composite is due to a superplasticity mechanism. An expression has been derived, taking into account the kinetics of refractory phase grain growth, relating the porosity ofa very finely divided composite to time of LPS under conditions of superplastic flow.
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Literature cited
V. N. Eremenko, R. V. Minakova, and M. M. Churakov, “Solubility of tungsten in copper-nickel melts,” Poroshk. Metall., No. 4, 53–58 (1977).
V. V. Panichkina, M. M. Sirotyuk, and V. V. Skorokhod, “Liquid-phase sintering of very fine tungsten-copper powder mixtures,” Poroshk, Metall., No. 6, 27–31 (1982).
V. V. Skorokhod, Powder Metallurgical Materials Based on Refractory Metals and Compounds [in Russian], Tekhnika, Kiev (1982).
W. A. Kaysser, M. Zivkovich, and G. Petzow, “Shape accommodation during grain growth in the presence of liquid phase,” J. Mater. Sci.,20, No. 2, 578–584 (1985).
V. V. Skorokhod and S. M. Solonin, Physicometallurgical Principles of Sintering of Powders [in Russian], Metallurgiya, Moscow (1984).
T. H. Courtney, “Densification and structural development in liquid phase sintering,” Metall. Trans.,15, No. 6, 1065–1075 (1984).
N. C. Kothary, “Densification and grain growth during liquid phase sintering of tungsten-nickel-copper alloys,” J. Less Common Met.,13u, No. 4, 457–468 (1967).
V. V. Skorokhod, V. V. Panichkina, and N. K. Prokushev, “Structural inhomogeneity and localization of densification in the liquid-phase sintering of tungsten-copper powder mixtures,” Poroshk. Metall., No. 8, 14–19 (1986).
K. S. Chernyavskii, Stereology in Metallurgy [in Russian], Metallurgiya, Moscow (1977).
H. Fischmeister, A. Kannapan, and Lai-Yi, “Grain growth during sintering of W-Cu-Ni alloys,” Phys. Sintering,51, No. 1, 1–13 (1969).
V. V. Skorokhod, Yu. M. Solonin, and N. I. Filippov, “Solid-phase sintering of ultrafine W(Mo)-Cu composite powders,” Poroshk. Metall., No. 1, 19–25 (1984).
V. V. Skorokhod, Yu. M. Solonin, N. I. Filippov, and A. N. Roshchin, “Sintering of tungsten-copper composites of various origins,” Poroshk. Metall., No. 9, 9–13 (1983).
V. V. Skorokhod, Rheological Principles of Sintering Theory [in Russian], Naukova Dumka, Kiev (1972).
M. G. Ashby and R. A. Verrall, “Diffusion-accommodated flow and superplasticity,” Acta Metall.,21, No. 2, 149–163 (1973).
A. Henjered, M. Hellsing, H.-O. Andren, and H. Norden, “The presence of cobalt at WC/WC interfaces,” in: Transactions of the Second International Conference on the Science of Hard Materials, Rhodes (1984).
N. K. Sharma, I. D. Ward, H. L. Fraser, and W. S. Williams, “Stem analysis of grain boundaries in cemented carbides,” J. Am. Ceram. Soc.,63, No. 3/4, 194–196 (1980),
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Translated from Poroshkovaya Metallurgiya, No. 9(285), pp. 30–37, September, 1986.
The authors wish to thank V. V. Skorokhod and V. V. Panichkina for helpful discussion.
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Prokushev, N.K., Smirnov, V.P. Kinetics of densification and growth of refractory phase grains in the liquid-phase sintering of very finely divided tungsten-copper materials. Powder Metall Met Ceram 25, 727–733 (1986). https://doi.org/10.1007/BF00797302
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DOI: https://doi.org/10.1007/BF00797302