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Densification of carbon-rich boron carbide nanopowder compacts

Published online by Cambridge University Press:  18 July 2011

Namtae Cho ,
Kathleen G. Silver ,
Yolande Berta ,
Robert F. Speyer ,
Noel Vanier  and
Cheng-Hung Hung
Namtae Cho
Affiliation:
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332
Kathleen G. Silver
Affiliation:
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332
Yolande Berta
Affiliation:
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332
Robert F. Speyer*
Affiliation:
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332
Noel Vanier
Affiliation:
PPG Industries, Inc., Allison Park, Pennsylvania 15101
Cheng-Hung Hung
Affiliation:
PPG Industries, Inc., Allison Park, Pennsylvania 15101
*
a) Address all correspondence to this author. e-mail: [email protected]
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Abstract

The densification behavior of 20–40-nm graphite-coated B4C nano-particles was studied using dilatometry, x-ray diffraction, and electron microscopy. The sintering onset temperature was higher than expected from a nanoscale powder (∼1500 °C); remnant B2O3 kept particles separated until B2O3 volatilization, and the graphite coatings imposed particle-to-particle contact of a substance more refractory than B4C. Solid-state sintering (1500–1850 °C) was followed by a substantial slowing of contraction rate attributed to the formation of eutectic liquid droplets more than 10× the size of the original nano-particles. These droplets were induced to form well below the B4C-graphite eutectic temperature by the high surface energy of nanoparticles. They were interpreted to have quickly solidified to form a vast number of voids in particle packing, which in turn, impeded detection of continued solid-state sintering. Starting at 2200 °C, a permanent and interconnected liquid phase formed, which facilitated rapid contraction by liquid phase sintering and/or compact slumping.

Keywords

NanoscaleSintering
Type
Articles
Information
Journal of Materials Research , Volume 22 , Issue 5 , May 2007 , pp. 1354 - 1359
Copyright
Copyright © Materials Research Society 2007

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References

REFERENCES

1Shackelford, J.F. and Alexander, W.: CRC Materials Science and Engineering Handbook (CRC Press, Boca Raton, FL, 1991).Google Scholar
2Thevenot, F.: Boron carbide—A comprehensive review. J. Eur. Ceram. Soc. 6, 205 (1990).Google Scholar
3Emin, D.: Structure and single-phase regime of boron carbide. Phys. Rev. B 31, 6041 (1988).CrossRefGoogle Scholar
4Skorokhod, V. Jr., Vlajic, M.D., and Krstic, V.D.: Mechanical properties of pressureless sintered boron carbide containing TiB2 phase. J. Mater. Sci. Lett. 15, 1337 (1996).CrossRefGoogle Scholar
5Lee, C.H. and Kim, C.H.: Pressureless sintering and related reaction phenomena of Al2O3–doped B4C. J. Mater. Sci. 27, 6335 (1992).CrossRefGoogle Scholar
6Kanno, Y., Kawase, K., and Nakano, K.: Additive effect on sintering of boron carbide. J. Ceram. Soc. Jpn. 95, 1137 (1987).Google Scholar
7Zakhariev, Z. and Radev, D.: Properties of polycrystalline boron carbide sintered in the presence of W2B5 without pressing. J. Mater. Sci. Lett. 7, 695 (1988).Google Scholar
8Schwetz, K. and Vogt, G.: Process for the production of dense sintered articles of boron carbide. U.S. Patent 4 195 066 (1980).Google Scholar
9Lee, H. and Speyer, R.F.: Pressureless sintering of boron carbide. J. Am. Ceram. Soc. 86, 1468 (2003).CrossRefGoogle Scholar
10Lee, H., Hackenberger, W.S., and Speyer, R.F.: Sintering of boron carbide heat-treated with hydrogen. J. Am. Ceram. Soc. 85, 2131 (2002).Google Scholar
11Cho, N., Bao, Z., and Speyer, R.F.: Density- and hardness-optimized pressureless sintered and post-hot isostatic pressed B4C. J. Mater. Res. 20, 2110 (2005).CrossRefGoogle Scholar
12Averbak, R.S., Hofler, H.J., Hahn, H., and Logas, J.C.: Sintering and grain growth in nanocrystlaline ceramics. Nanostruct. Mater. 1, 173 (1992).CrossRefGoogle Scholar
13Vasylkiv, O., Sakka, Y., and Skorokhod, V.V.: Low-temperature processing and mechanical properties of zirconia and zirconia-alumina nanoceramics. J. Am. Ceram. Soc. 86, 299 (2003).CrossRefGoogle Scholar
14Bourell, D.L., Parimal, , and Kaysser, W.: Sol-gel synthesis of nanophase yttria-stabilized tetragonal zirconia and densification behavior below 1600 K. J. Am. Ceram. Soc. 76, 705 (1993).CrossRefGoogle Scholar
15Groza, J.R. and Dowding, R.J.: Nanoparticulate materials densification. Nanostruct. Mater. 7, 749 (1996).Google Scholar
16Kim, B.N., Hiraga, K., Morita, K., and Sakka, S.: A high strain rate superplastic ceramic. Nature 413, 288 (2001).Google Scholar
17Xu, X., Nishimura, T., Hirosaki, N., Xie, R-J., Yamamoto, Y., and Tanaka, H.: Superplastic deformation of nano-sized silicon nitride ceramics. Acta Mater. 54, 255 (2006).Google Scholar
18Rice, R.W.: Effects of environment and temperature on ceramic tensile strength-grain size relations. J. Mater. Sci. 32, 3071 (1997).Google Scholar
19Chang, H., Hofler, J., Alstetter, C., and Averbak, R.: Synthesis, processing and properties of nanophase aluminide. Mater. Sci. Eng., A 153, 676 (1992).CrossRefGoogle Scholar
20Gonzalez, E.J., Hockey, B., and Piermarini, G.J.: High pressure compaction and sintering of nano-size gamma-Al2O3 powder. Mater. Manuf. Proc. 11, 951 (1996).CrossRefGoogle Scholar
21Wolff, M., Braun, A., Bartscherer, E., and Clasen, R.: Preparation of polycrystalline ceramic compacts made of alumina powder with a bimodal particle size distribution for hot isostatic pressing. Ceram. Eng. Sci. Proc. 24, 81 (2003).CrossRefGoogle Scholar
22Williams, P.D. and Hawn, D.D.: Aqueous dispersion and slip casting of boron carbide powder: Effect of pH and oxygen content. J. Am. Ceram. Soc. 74, 1614 (1991).Google Scholar
23CRC Handbook of Chemistry and Physics 58th ed., edited by Weast, R.C. (CRC Press, Cleveland, OH, 1977).Google Scholar
24Edington, J.W.: Practical Electron Microscopy in Materials Science (Van Nostrand Reinhold, New York, 1976), pp. 27–29.Google Scholar
25Samsonov, G.V.: Metallphys. Metallkund. SSSR Ural Filial 3–S, 309 (1956),Google Scholar
as cited by Shaffer, T.B.: Engineering properties of carbides, in Engineered Materials Handbook, Vol. 4, Ceramics and Glasses edited by Schneider, S.H. (ASM International, Materials Park, OH, 1991) pp. 804–811.Google Scholar