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Theory and technology of sintering, thermal and chemicothermal treatment

Densification of WC-Co alloys in solid-phase sintering (review)

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Powder Metallurgy and Metal Ceramics Aims and scope

Abstract

The studies on the densification of WC-Co alloys in solid-phase sintering are analyzed. It is shown that solid-phase sintering of alloys with tungsten carbide particles smaller than 2.0 µm is characterized by high densification (shrinkage) and results in compact samples in some cases. Shrinkage is established to be nonmonotonic over a wide range of sintering temperatures. There are at least three different stages of densification over the range from room to solidus temperatures. Approximate temperature ranges for densification stages are 100 to 1050 °C, 1050 to 1200 °C, and 1200 °C to the eutectic melting temperature. The stages mainly differ in the extent and rate of shrinkage and in the activation energy. The compaction stages are separated by characteristic temperatures. The most important is 1200 °C, which separates the second and the third stages. The maximum rate of shrinkage is observed mostly at this temperature. The variation of initial WC particles from 5 to 2000 nm does not significantly affect the temperature at which the solid-phase shrinkage rate is maximum. In most cases, there are two maximum rates of shrinkage in WC-Co sintering: one at 1200 ± 30 °C and the other at the solidus temperature.

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References

  1. G. E. Spriggs, “A history of fine grained hardmetal,” Int. J. Refractory Metals & Hard Materials, 13, No. 5, 241–255 (1995).

    Article  CAS  Google Scholar 

  2. W. D. Schubert, A. Bock, and B. Lux, “General aspects and limits of conventional ultrafine WC powder manufacture and hard metal production,” in: Proc. 13th Int. Plansee Seminar, H. Bildstein and R. Eck (eds.), Vol. 4, Metallwerk Plansee, Reutte (1993), pp. 283–305.

    Google Scholar 

  3. L. E. Mc Candlish, B. H. Kear, and B. K. Kim, “Chemical processing of nanophase WC-Co composite powders,” Mater. Sci. Techn., 6, No. 10, 953–957 (1990).

    Google Scholar 

  4. V. I. Tretyakov, Fundamentals of Physical Metallurgy and Production Technology of Hard Sintered Alloys [in Russian], Metallurgy, Moscow (1976), p. 528.

    Google Scholar 

  5. M. M. Babich, Nonuniform Carbon Content in Hard Alloys and Its Homogenization [in Russian], Naukova Dumka, Kiev (1975), p. 176.

    Google Scholar 

  6. R. F. Snowball and D. R. Milner, “Densification processes in the tungsten carbide-cobalt system,” Powder Metallurgy, 11, No. 21, 23–40 (1968).

    CAS  Google Scholar 

  7. J. Gurland and D. J. Norton, J. Metals, 4, No. 10, 1051–1056 (1952).

    CAS  Google Scholar 

  8. I. N. Chaporova and K. S. Chernyavskii, Structure of Hard Sintered Alloys [in Russian], Metallurgy, Moscow (1975), p. 248.

    Google Scholar 

  9. S. Roure and J. M. Missiaen, “Macroscopic and microstructural evolution of WC-Co compacts during solid state sintering,” in: Proc. Euro PM’96, Stockholm (1986), pp. 77–84.

  10. S. Haglund, B. Uhrenius, and J. Agren, “Solid state sintering of WC-Co,” in: Proc. PM’94, Powder Metallurgy World Congress (June 6–9, 1994), Vol. 2, Paris (1994), pp. 1493–1496.

    Google Scholar 

  11. S. Haglund, J. Agren, and B. Uhrenius, “Solid state sintering of cemented carbides — an experimental study,” Z. Metallk., 89, No. 5, 316–322 (1998).

    CAS  Google Scholar 

  12. S. M. Missiaen and S. Roure, “A general morphological approach of sintering kinetics: application to WC-Co solid phase sintering,” Acta Mater., 46, No. 11, 3985–3993 (1998).

    Article  CAS  Google Scholar 

  13. G. Leitner, T. Gestrich, and G. Gille, “Shrinkage, liquid phase formation and gaseous reactions during sintering of WC-Co hardmetals and correlation to the WC grain size,” in: Proc. 14th Int. Plansee Seminar (May 12–16, 1997), Vol. 2, Reutte, Tirol (1997), pp. 86–99.

    Google Scholar 

  14. G. Gille, B. Szesny, and G. Leitner, “A new 0.4 µm WC powder as well as powder-related properties and sintering behavior of 0.6 to 30 µm WC-Co hardmetals,” in: Proc. 14th Int. Plansee Seminar (May 12–16, 1997), Reutte, Tirol (1997), pp. 139–167.

  15. R. Porat, S. Berger, and A. Rosen, “Synthesis and processing of nanocrystalline WC-Co powders,” in: Proc. 14th Int. Plansee Seminar (May 12–16, 1997), Reutte, Tirol (1997), pp. 582–595.

  16. L. E. Mc Candlish, B. H. Kear, and B. K. Kim, “Carbothermic reaction process for making nanophase WC-Co powders,” Pat. No. 5230729 USA, Publ. July 27, 1993.

  17. G. Gille, B. Szesny, K. Dreyer, et al., “Submicron and ultrafine grained hardmetal for microdrills and metal cutting insert,” in: Proc. 15th Int. Plansee Seminar (May 28–June 1, 2001), Vol. 2, Reutte (2001), pp. 782–816.

    Google Scholar 

  18. A. V. Laptev, “Solid-state consolidation of WC-Co hardmetals. Peculiarities and prospects,” in: Science for Materials in the Frontier of Centuries: Advantages and Challenges: Proc. Int. Conf. (November 4–8, 2002), Vol. 2, Kyiv (2002), pp. 491–492.

    CAS  Google Scholar 

  19. O. Lavergne, F. Hodaj, and C. H. Allibert, “Solid state dissolution behavior of WC in Co binder,” in: Proc. Euro PM’96, Stockholm (1986), pp. 153–158.

  20. V. V. Skorokhod and S. M. Solonin, Fundamental Physics and Metallurgy of Powder Sintering [in Russian], Metallurgy, Moscow (1984), p. 158.

    Google Scholar 

  21. G. Chavdarov and N. Rasskazov, “Compaction of WC-Co hard alloys in hot pressing without a liquid phase, ” Annual of the Nonferrous Metallurgy Institute, 21, 110–116 (1983).

    Google Scholar 

  22. N. Tsuchiya, M. Fukuda, T. Nakai, and H. Suzuki, “Some properties of WC-Co alloy prepared by solid-phase sintering,” J. Jap. Soc. Powder and Powder Metall., 37, No. 8, 1177–1180 (1990).

    CAS  Google Scholar 

  23. J. Azcona, A. Ordonez, L. Dominguez, et al., “Hot isostatic pressing of nanosized WC-Co Hardmetals, ” in: Proc. 15th Int. Plansee Seminar, Vol. 2, Reutte (2001), pp. 35–49.

    Google Scholar 

  24. A. V. Laptev, S. S. Ponomarev, and L. F. Ochkas, “Structural features and properties of alloy 84% WC-16% Co obtained by hot pressing in the solid and liquid phases. Part 1. Effect of the temperature at which the specimens are prepared on their density and structure,” Powder Metall. Met. Ceram., 39, No. 11–12, 607–617 (2000).

    Article  CAS  Google Scholar 

  25. A. V. Laptev, S. S. Ponomarev, and L. F. Ochkas, “Solid phase consolidation fine grained WC-16 wt.% Co hard metals,” J. Advan. Mat., 33, No. 3, 42–51 (2001).

    CAS  Google Scholar 

  26. A. V. Laptev, S. S. Ponomarev, and L. F. Ochkas, “Study of possibility of solid phase producing porousless WC-26% Co hard metal at high energy pressing,” in: Proc. EURO PM’99, Conf. on Advances in Hard Materials Production (November 8–10, 1999), Turin, Italy (1999), pp. 205–212.

  27. V. M. Dotsenko, A. R. Kryuchkova, V. L. Ishchuk, et al., “Some properties and structural features of hard alloys produced under high pressures,” in: Effect of High Pressure on Matter [in Russian], Naukova Dumka, Kiev (1978), pp. 91–94.

    Google Scholar 

  28. A. K. Butylenko and V. N. Sokolovskii, “Densification of tungsten and titanium carbides and their mixtures with nickel during heating under high pressure,” Powder Metall. Met. Ceram., 20, No. 7, 466–469 (1981).

    Google Scholar 

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  1. Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, Kiev

    A. V. Laptev

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Translated from Poroshkovaya Metallurgiya, Vol. 46, No. 7–8 (456), pp. 8–18, 2007.

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Laptev, A.V. Theory and technology of sintering, thermal and chemicothermal treatment. Powder Metall Met Ceram 46, 317–324 (2007). https://doi.org/10.1007/s11106-007-0051-3

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