Hardness and deformation microstructures of nano-polycrystalline diamonds synthesized from various carbons under high pressure and high temperature

Abstract

Mechanical properties of high-purity nano-polycrystalline diamonds synthesized by direct conversion from graphite and various non-graphitic carbons under static high pressures and high temperatures were investigated by microindentation testing with a Knoop indenter and observation of microstructures around the indentations. Results of indentation hardness tests using a superhard synthetic diamond Knoop indenter showed that the polycrystalline diamond synthesized from graphite at ⩾15 GPa and 2300–2500 °C (consisting of fine grains 10–30 nm in size and layered crystals) has very high Knoop hardness (Hk ⩾ 110 GPa), whereas the hardness of polycrystalline diamonds synthesized from non-graphitic carbons at ⩾15 GPa and below 2000 °C (consisting only of single-nano grains 5–10 nm in size) are significantly lower (Hk = 70 to 90 GPa). Microstructure observations beneath the indentations of these nano-polycrystalline diamonds suggest that the existence of a lamellar structure and the bonding strength of the grain boundary play important roles in controlling the hardness of the polycrystalline diamond.

This is a preview of subscription content, access via your institution.

FIG. 1
FIG. 2
TABLE I.
FIG. 3
FIG. 4
FIG. 5
FIG. 6
FIG. 7
FIG. 8

References

  1. 1

    T. Irifune, A. Kurio, S. Sakamoto, T. Inoue H. Sumiya: Ultrahard polycrystalline diamond from graphite. Nature 421, 599 2003

    CAS  Article  Google Scholar 

  2. 2

    H. Sumiya, T. Irifune, A. Kurio, S. Sakamoto T. Inoue: Microstructure features of polycrystalline diamond synthesized directly from graphite under static high pressure. J. Mater. Sci. 39, 445 2004

    CAS  Article  Google Scholar 

  3. 3

    H. Sumiya T. Irifune: Indentation hardness of nano-polycrystalline diamond prepared from graphite by direct conversion. Diamond Relat. Mater. 13, 1771 2004

    CAS  Article  Google Scholar 

  4. 4

    S. Naka, K. Horii, Y. Takeda T. Hanawa: Direct conversion of graphite to diamond under static pressure. Nature 259, 38 1976

    CAS  Article  Google Scholar 

  5. 5

    A. Onodera, K. Higashi Y. Irie: Crystallization of amorphous carbon at high static pressure and high temperature. J. Mater. Sci. 23, 422 1988

    CAS  Article  Google Scholar 

  6. 6

    H. Yusa, K. Takemura, Y. Matsui, H. Morishima, K. Watanabe, H. Yamawaki K. Aoki: Direct transformation of graphite to cubic diamond observed in a laser-heated diamond anvil cell. Appl. Phys. Lett. 72, 1843 1998

    CAS  Article  Google Scholar 

  7. 7

    H. Yusa: Nanocrystalline diamond directly transformed from carbon nanotubes under high pressure. Diamond Relat. Mater. 11, 87 2002

    CAS  Article  Google Scholar 

  8. 8

    N. Dubrovinskaia, L. Dubrovinsky, F. Langenhorst, S. Jacobsen C. Liebske: Nanocrystalline diamond synthesized from C60. Diamond Relat. Mater. 14, 16 2005

    CAS  Article  Google Scholar 

  9. 9

    H. Sumiya, H. Yusa, T. Inoue, H. Ofuji T. Irifune: Conditions and mechanism of formation nano-polycrystalline diamonds directly from graphite and non-graphitic carbon at high-pressure and high-temperature. J. High Press. Res. 26, 63 2006

    CAS  Article  Google Scholar 

  10. 10

    N. Kawai S. Endo: The generation of ultra hydrostatic pressure by a split sphere apparatus. Rev. Sci. Instrum. 41, 1178 1970

    CAS  Article  Google Scholar 

  11. 11

    T. Irifune H. Sumiya: Nature of polycrystalline diamond synthesized by direct conversion of graphite using Kawai-type multianvil apparatus. New Diamond Frontier Carbon Technol. 14, 313 2004

    CAS  Google Scholar 

  12. 12

    H. Sumiya: Super-hard diamond indenter prepared from high-purity synthetic diamond crystal. Rev. Sci. Instrum. 76, 026112 2005

    Article  Google Scholar 

  13. 13

    H. Sumiya, N. Toda S. Satoh: Mechanical properties of synthetic type IIa diamond crystal. Diamond Relat. Mater. 6, 1841 1997

    CAS  Article  Google Scholar 

  14. 14

    H. Sumiya, K. Yamaguch S. Ogata: Deformation microstructure of high-quality synthetic diamond crystal subjected to Knoop indentation. Appl. Phys. Lett. 88, 161904 2006

    Article  Google Scholar 

  15. 15

    N. Dubrovinskaia, L. Dubrovinsky, W. Crichton, F. Langenhorst A. Richter: Aggregated diamond nanorods, the densest and least compressible form of carbon. Appl. Phys. Lett. 87, 083106 2005

    Article  Google Scholar 

  16. 16

    N. Dubrovinskaia, S. Dub L. Dubrovinsky: Super wear resistance of aggregated diamond nanorods. Nano Lett. 6, 824 2006

    CAS  Article  Google Scholar 

  17. 17

    S. Veprek: Nanostructured superhard materials in Handbook of Ceramic Hard Materials edited by R. Riedel, Wiley-VCH Vch Verlagsgesellschaft Mbh 2000 104

    Google Scholar 

  18. 18

    S. Yip: The strongest size. Nature 391, 532 1998

    CAS  Article  Google Scholar 

Download references

ACKNOWLEDGMENTS

The authors thank H. Yusa, T. Inoue, H. Ofuji, and K. Harano for their help with this study. This work was partially supported by a grant from the New Energy and Industrial Technology Development Organization, Japan (NEDO).

Author information

Affiliations

Authors

Corresponding author

Correspondence to H. Sumiya.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Sumiya, H., Irifune, T. Hardness and deformation microstructures of nano-polycrystalline diamonds synthesized from various carbons under high pressure and high temperature. Journal of Materials Research 22, 2345–2351 (2007). https://doi.org/10.1557/jmr.2007.0295

Download citation