Densification of Alumina Ceramics Sintered by Using Submillimeter Wave Gyrotron

  • I. N. Sudiana
  • R. Ito
  • S. Inagaki
  • K. Kuwayama
  • K. Sako
  • S. Mitsudo


The sintering of high purity alumina, by using a very high frequency in range sub-millimeter waves, is presented in this paper. The sintering was performed by using a 300 GHz material processing system. Achieving homogeneous and volumetric heating on submillimeter wave sintering was confirmed by the grain size distribution analysis. The densification curves were obtained for submillimeter wave (300 GHz), millimeter wave (28 GHz), and conventional processing. The enhancement of densification and early shrinkage were observed on submillimeter wave sintering. However, compared with millimeter wave method, the densification of sub-millimeter wave sintering is lower at all sintering temperatures. The grain coarsening was analyzed using SEM photographs of fracture surfaces. The grain sizes of submillimeter wave sintered samples were smaller than those of the millimeter wave sintered samples. The effect of cold isostatic pressing, was also evaluated on submillimeter wave sintering. It suggests that the cold isostatic pressing method is quite effective for densification of SMMW sintering alumina.


Submillimeter wave Alumina Densification Cold isostatic pressing Gyrotron 



This work was supported partially by Special Fund for Education and Research from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan. The authors also would like to acknowledge Prof. H. Aripin from Siliwangi University, Indonesia and Prof. M. Glyavin from Institute of Applied Physics of Russian Academy of Sciences, Nizhny Novgorod, Russia for valuable discussions.


  1. 1.
    D.E. Clark and D.C. Foltz, “What is microwave processing?”, in Microwave Solutions for Ceramic Engineers, edited by D. E. Clark, D. C. Folz, C. E. Folgar, and M. M. Mahmoud, American Ceramic Society, Ohio, p.1-32 (2005).Google Scholar
  2. 2.
    G. Link, L. Feher, M. Thumm, H. J. Ritzhaupt-Kleissl, R. Bohme, and A. Weisenburger, “Sintering of Advanced Ceramics Using a 30-GHz, 10-kW, CW Industrial Gyrotron”, IEEE Trans. on Plasma Science, 27[ 2], pp 547-554 (1999).CrossRefGoogle Scholar
  3. 3.
    G. link, L. Feher, M.Thumm,“Hot Wall 30 GHz Cavity for Homogenous High Temperature Heating,” Proc. Int. Conf. Microwave and High Frequency Heating, Valencia, Sept. 13-17, pp. 165-168 (1999).Google Scholar
  4. 4.
    W. H. Sutton, “Microwave processing of ceramic materials”, in Microwave Solutions for Ceramic Engineers, edited by D. E. Clark, D. C. Folz, C. E. Folgar, and M. M. Mahmoud, American Ceramic Society, Ohio, p.35-65 (2005).Google Scholar
  5. 5.
    H.D. Kimrey and M.A. Janney, “Design principles for high-frequency microwave cavities”, Materials Research Society, volume 124, p. 367-372, Pittsburg(1988).Google Scholar
  6. 6.
    M. Glyavin, Yu. Bykov, D. Denisov, A. Eremeev, T. Idehara, S. Mitsudo, and H. Hoshizuki, “Development of a compact gyrotron system for microwave processing of materials”, J. Japan Society of Infrared Science and Technology, 12[1] (2002). Pp. 60-64.Google Scholar
  7. 7.
    S. Mitsudo, H. Hoshizuki, T. Idehara, T. Saito, “Development of material processing system by using a 300 GHz CW gyrotron”, J. of Phys.: Conference Series, 52, 549 – 552 (2006).CrossRefGoogle Scholar
  8. 8.
    S. Tani, “Characterization of zirconia ceramics sintered by a high power sub-millimeter wave”, Master Thesis, Faculty of Engineering, University of Fukui (2010) [in Japanese].Google Scholar
  9. 9.
    S. Mitsudo, K. Sako, S. Tani, I.N. Sudiana, “High power pulsed sub-millimeter wave sintering of zirconia ceramics“, The 36th Int. Conf. on Infrared, Millimeter and THz Waves (IRMMW-THz 2011), Hyatt Regency Houston, Houston, Texas, USA, Oct. 2-7, 2011.Google Scholar
  10. 10.
    H. Aripin, S. Mitsudo, I.N. Sudiana, S. Tani, K. Sako, Y. Fujii, T. Saito, T. Idehara, “Rapid sintering of silica xerogel ceramic derived from sago waste ash using sub-millimeter wave heating of a 300 GHz CW gyrotron”, Int. J. of Infrared and Millimeter waves, DOI 10.1007/s10762-011-9797-2 (2011)Google Scholar
  11. 11.
    W.W. Ho, “High temperature dielectric properties of polycrystalline ceramics”, Mater. Res. Soc. Proc. 124, 137(1988).CrossRefGoogle Scholar
  12. 12.
    M. A. Janney and H. D. Kimrey, “Microwave sintering of alumina at 28 GHz”, Ceramic Powder Science, II, p. 919-924, Ohio, 1988.Google Scholar
  13. 13.
    S. Sano, Y. Makino, S. Miyake, Y. V. Bykov, A. G. Eremeev, S. V. Egorov,”30 and 83 GHz millimeter wave sintering of alumina”, J. Materials Science Letters, 19, 2247 – 2250(2000).CrossRefGoogle Scholar
  14. 14.
    A. Shui, A. Makiya, S. Tanaka, N. Uchida, and K. Uematsu, “Effect of cold isostatic pressing on microstructure and shrinkage anisotropy during sintering of unaxially pressed alumina compacts”, J. Ceramic Society of Japan, 110[4], p. 264-269 (2002).CrossRefGoogle Scholar
  15. 15.
    T. Saito, T. Nakano, H. Hoshizuki, K. Sakai, Y. Tatematsu, S. Mitsudo, I. Ogawa, T. Idehara, V. E. Zapevalov, “Performance test of CW 300 GHz gyrotron FU CW I”, Inter. J. of Infrared and Millimeter waves, 28,1063–107 (2007).CrossRefGoogle Scholar
  16. 16.
    K. Sako, Y. Kobayashi, S. Hashimoto, T. Nakano, S. Mitsudo, Y. Tatematsu,T. Idehara, T. Saito “Development of a material heating system by using a 300 GHz gyrotron FU CW I”, 35th Inter. Conf. on Infrared Millimeter and Terahertz Waves, Busan, Korea, 21-25 September 2009.Google Scholar
  17. 17.
    ASTM Standard C373 - 88(2006) “Standard test method for water absorption, bulk density, apparent porosity and apparent specific gravity of fired whiteware products”, ASTM International, West Conshohocken, PA, 2006.Google Scholar
  18. 18.
    K. H. Brosnan, G. L. Messing, D. K. Agrawal, “Microwave sintering of alumina at 2.45 GHz”, J. American Ceramic Society ,86 [8], p. 1307–1312, August 2003.Google Scholar
  19. 19.
    R. M. German, “Sintering theory and practice”, John Wiley, New York (1996).Google Scholar
  20. 20.
    R. L. Coble, “Sintering crystalline solids. I. Intermediate and final state diffusion models”, J. Appl. Phys. 32 (1961) [5], pp.787-792Google Scholar
  21. 21.
    R. L. Coble, “Sintering crystalline solids. II. Experimental test of diffusion models in powder compacts”, J. Appl. Phys. 32 (1961) [5], pp.793-799.Google Scholar
  22. 22.
    J. R. Brandon, J. Samuels, and W. R. Hodgkins, “Microwave Sintering of Oxide Ceramics, Mater. Res. Soc. Proc. 269, p237 (1992).CrossRefGoogle Scholar
  23. 23.
    M.A. Janney and H.D. Kimrey, “Diffusion-controlled processes in microwave-fired oxide ceramics”, Mater. Res.Soc.Proc. 189, 215-227 (1990).CrossRefGoogle Scholar
  24. 24.
    Yu. V. Bykov, A. L. Goldenberg and V. A. Flyagin, “The possibilities of material processing by intense millimeter-wave radiation,” paper presented at the Materials Research Society Spring Meeting, symposium on Microwave Processing of Materials, April 17-20, San Francisco (1990).Google Scholar

Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • I. N. Sudiana
    • 1
  • R. Ito
    • 1
  • S. Inagaki
    • 1
  • K. Kuwayama
    • 1
  • K. Sako
    • 1
  • S. Mitsudo
    • 1
  1. 1.Research Center for Development of Far Infrared RegionUniversity of FukuiFukuiJapan

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