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Defect structure evolution and abnormal grain growth during spark plasma sintering of nano WC–Si powders

Published online by Cambridge University Press:  12 April 2016

A.K. Nanda Kumar*
Affiliation:
Functional Materials Division, CSIR-CECRI, Karaikudi 630 003, India
B. Subramanian
Affiliation:
Functional Materials Division, CSIR-CECRI, Karaikudi 630 003, India
Kazuya Kurokawa
Affiliation:
National Institute of Technology, Tomakomai College, Nishikioka, Tomakomai 059 1275, Japan
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

The microstructural evolution during spark plasma sintering of ultrafine WC–1 wt% Si (n-WC–Si) is presented. At 1323 K (T < TmSi), extensive stacking faults on the $\left\{ {10\bar 10} \right\}$ prismatic planes are observed. The defect microstructure can be described as a combined shear of $1/6\left\langle {\bar 12\bar 13} \right\rangle$ on the prism planes and simultaneous out-diffusion of carbon through the faults to the interparticle boundaries. At temperatures near TmSi (1673 K), a large fraction of abnormally grown platelets is observed. These platelets contain a single planar defect on their basal planes, described by a ${1 \mathord{\left/ {\vphantom {1 3}} \right. \kern-\nulldelimiterspace} 3}\left\langle {10\bar 10} \right\rangle$ translation of the carbon atoms across a Σ1 grain boundary (GB). Three factors contribute to the abnormally high density of platelets: (i) the low-temperature prismatic dislocations interact to form facet-roughening steps/kinks that act as nucleation sites, (ii) a liquid phase triggers an increased growth rate in the vicinity of the Si inclusions, and (c) the basal twin produces a re-entrant edge for 2D nucleation.

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Articles
Copyright
Copyright © Materials Research Society 2016 

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References

REFERENCES

Yuan, X., Rohrer, G., Song, X., Chien, H., and Li, J.: Modelling the interface area aspect ratio of carbide grains in WC–Co composites. Int. J. Refract. Met. Hard Mater. 44, 7 (2014).CrossRefGoogle Scholar
Yoon, B.-K., Lee, B.-A., and Kang, S.-J.L.: Growth behavior of rounded (Ti, W)C and faceted WC grains in a Co matrix during liquid phase sintering. Acta Mater. 53, 4677 (2005).CrossRefGoogle Scholar
Li, Z., Shu, C., Yuan-jie, W., Xian-wang, Y., and Xiang-jun, X.: Tungsten carbide platelet-containing cemented carbide with yttrium containing dispersed phase. Trans. Nonferrous Met. Soc. China 18, 104 (2008).Google Scholar
Cha, S.I. and Hong, S.H.: Microstructures of binder-less tungsten carbides sintered by spark plasma sintering process. Mater. Sci. Eng., A 356, 381 (2003).CrossRefGoogle Scholar
Girardini, L., Zadra, M., Casari, F., and Molinari, A.: SPS, binderless WC powders and the problem of the sub-carbide. Met. Powder Rep. 63, 18 (2008).CrossRefGoogle Scholar
Jo, W., Kim, D.-Y., and Hwang, N.-M.: Effect of interface structure on the microstructural evolution of ceramics. J. Am. Ceram. Soc. 89, 2369 (2006).CrossRefGoogle Scholar
Kang, S.-J., Lee, M.-G., and Yan, S.-M.: Microstructural evolution during sintering with control of the interface structure. J. Am. Ceram. Soc. 92, 1464 (2009).CrossRefGoogle Scholar
Oh, K.-S., Jun, J.-Y., Kim, D.-Y., and Hwang, N.M.: Shape dependence of the coarsening behavior of niobium carbide grains dispersed in liquid iron matrix. J. Am. Ceram. Soc. 83, 317 (2000).CrossRefGoogle Scholar
Nanda Kumar, A.K., Watabe, M., and Kurokawa, K.: Effect of boron on the microstructure of spark plasma sintered ultrafine WC. Vacuum 88, 88 (2013).CrossRefGoogle Scholar
Lay, S. and Loubradou, M.: Structural analysis on planar defects formed in WC platelets in Ti-doped WC–Co. J. Am. Ceram. Soc. 89, 3229 (2006).CrossRefGoogle Scholar
Nanda Kumar, A.K., Watabe, M., and Kurokawa, K.: The sintering kinetics of n-WC–Si and n-WC–B. J. App. Plasma Sci. 18, 83 (2010).Google Scholar
Nanda Kumar, A.K., Watabe, M., Yamauchi, A., Kobayashi, A., and Kurokawa, K.: Spark plasma sintering of binderless n-WC and n-WC–X (X = Nb, Re, Ta, Ti, B, Si). Trans. Joining and Welding Research Institute, Japan 39, 47 (2010).Google Scholar
Nino, A., Nakaibayashi, Y., Sugiyama, S., and Taimatsu, H.: Microstructure and mechanical properties of WC–SiC composites. Mater. Trans. 52, 1641 (2011).CrossRefGoogle Scholar
Sugiyama, S., Kudo, D., and Taimatsu, H.: Preparation of WC–SiC whisker composites by hot pressing and their mechanical properties. Mater. Trans. 49, 1644 (2008).CrossRefGoogle Scholar
Nanda Kumar, A.K., Watabe, M., and Kurokawa, K.: Influence of silicon on the microstructure and sintering kinetics of ultrafine tungsten carbide powders. Philos. Mag. A, 92, 3950 (2012).CrossRefGoogle Scholar
Lai, K.-R. and Tien, T.-Y.: Kinetics of β-Si3N4 grain growth in Si3N4 ceramics sintered under high nitrogen pressure. J. Am. Ceram. Soc. 76, 91 (1993).CrossRefGoogle Scholar
Hibbs, M.K. and Sinclair, R.: Room temperature deformation mechanisms and the defect structure of tungsten carbide. Acta Metall. 29, 1645 (1981).CrossRefGoogle Scholar
Jayaram, V., Sinclair, R., and Rowcliffe, J.: Deformation enhanced decarburization of WC–Co. Scr. Metall. 20, 55 (1986).CrossRefGoogle Scholar
Zhi-min, Y., Chang-hui, M., Jun, D., Daniel, M., Yannick, C., Serge, H., and Martin, H.: Trans. Nonferrous Met. Soc. China. 11, 529 (2001).Google Scholar
Gai, P.L., Torardi, C.C., and Boyes, E.D.: Turning points in solid-state materials and surface science, Harris, K.D.M. and Edwards, P.P. eds.; RSC Publication, 2008; p. 745.Google Scholar
Gao, Y., Song, X., Liu, X., Wei, C., Wang, H., and Guo, G.: On the formation of WC1−x in nanocrystalline cemented carbides. Scr. Mater. 68, 108 (2013).CrossRefGoogle Scholar
Vineesh, T.V., Praveen Kumar, M., Takahashi, C., Kalita, G., Alwarappan, S., Pattanayak, D.K., and Narayanan, T.N.: Bifunctional electrocatalytic activity of boron-doped graphene derived from boron carbide. Adv. Energy Mater. 5, 1500658 (2015).CrossRefGoogle Scholar
Bolton, J.D. and Redington, M.: Plastic deformation mechanisms in tungsten carbide. J. Mater. Sci. 15, 3150 (1980).CrossRefGoogle Scholar
Greenwood, R.M., Loretto, M.H., and Smallman, R.E.: The defect structure of tungsten carbide in deformed tungsten carbide-cobalt composites. Acta Metall. 30, 1193 (1982).CrossRefGoogle Scholar
Nabarro, F.R.N., Bartolucci Luyckx, S., and Waghmare, U.V.: Slip in tungsten monocarbide II. A first-principles study. Mater. Sci. Eng., A 483–484, 9 (2008).CrossRefGoogle Scholar
Lewis, D. and Porter, L.J.: Plastic deformation in tungsten carbide. J. Appl. Crystallogr. 2, 249 (1969).CrossRefGoogle Scholar
Sommer, M., Schubert, W.-D., Zobetz, E., and Warbichler, P.: On the formation of very large crystals during sintering of ultrafine WC–Co alloys. Int. J. Refract. Met. Hard Mater. 20, 4150 (2002).CrossRefGoogle Scholar
Young, R.M. and McPherson, R.: Temperature gradient-driven diffusion in rapid-rate sintering. J. Am. Ceram. Soc. 72, 1080 (1989).CrossRefGoogle Scholar
Olevsky, E.A. and Froyen, L.: Impact of thermal diffusion on densification during SPS. J. Am. Ceram. Soc. 92(S1), S122(2009).CrossRefGoogle Scholar
Andon, R.J.L., Martin, J.F., Mills, K.C., and Jenkins, T.R.: Heat capacity and entropy of tungsten carbide. I. Chem. Thermodyn. 7, 1079 (1975).CrossRefGoogle Scholar
Grebenkina, V.G. and Denbnovetskaya, E.N.: Temperature coefficient of electrical resistivity of some complex carbides. Translated from Poroshkovaya Met. 3(63) 34 (1968).CrossRefGoogle Scholar
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