Microwave-assisted alumina-zirconia brazed joint for microwave tubes


Alumina-zirconia joint was fabricated by microwave-assisted brazing technique at 980 °C for 15 min using TICUSIL (68.8Ag26.7Cu4.5Ti in wt%) as the brazing alloy. The brazed joints were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, Vickers microhardness evaluation, brazing strength measurement, and helium leak test. X-ray diffraction analysis confirmed the formation of Ti-based compounds at the substrate-filler alloy interfaces of the brazed joints. SEM images showed the substrate-filler alloy interfaces of the brazed joints. The EDX analysis determined the elemental compositions along the joint cross-section. Vickers microhardness measurement indicated reliable joint performance for the microwave-assisted brazed joints during actual application. Brazing strength measurement and helium leak test proved the formation of sound alumina-zirconia brazed joint by both microwave and conventional heating techniques. Scratch tests were performed on the cross-sectional surfaces of the alumina-zirconia joints. Scratch test results established the strong interfacial strength of the microwave brazed joints.

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  1. 1.

    Dandapat, N., Ghosh, S., Pal, K.S., Datta, S., Guha, B.K.: Thermal cycling behavior of alumina-graphite brazed joints in electron tube applications. Trans. Nonferrous Metals Soc. China. 24, 1666–1673 (2014)

    CAS  Article  Google Scholar 

  2. 2.

    Katz, J.D.: Microwave sintering of ceramics. Annu. Rev. Mater. Sci. 22, 153–170 (1992)

    CAS  Article  Google Scholar 

  3. 3.

    Clark, D., Sutton, W.H.: Microwave processing of materials. Annu. Rev. Mater. Sci. 26, 299–331 (1996)

    CAS  Article  Google Scholar 

  4. 4.

    Siores, E., Rego, D.D.: Microwave applications in materials joining. J. Mater. Process. Technol. 48, 619–625 (1995)

    Article  Google Scholar 

  5. 5.

    Clark, D.E., Folz, D.C., Schuiz, R.L., Fathi, Z., Cozzi, A.D.: Recent developments in the microwave processing of ceramics. MRS Bull. 18, 41–46 (1993)

    CAS  Article  Google Scholar 

  6. 6.

    Janney, M.A., Jackson, M.L., Kimrey, H.D.: Microwave sintering of ZrO2-12 mol% CeO2. In: Clark, D.E., Tinga, W.R., Laia Jr., J.R. (eds.) Microwaves: Theory and Applications in Materials Processing II, pp. 101–108. American Ceramic Society, Westerville (1993)

    Google Scholar 

  7. 7.

    Fukushima, H., Yamanaka, T., Matsui, M.: Microwave heating of ceramics and its application to joining. J. Mater. Res. 5, 397–405 (1990)

    CAS  Article  Google Scholar 

  8. 8.

    Silberglitt, R., Ahmad, I., Black, W.M., Katz, J.D.: Recent developments in microwave joining. MRS Bull. 18, 47–50 (1993)

    CAS  Google Scholar 

  9. 9.

    Cozzi, D., Clark, D.E., Ferber, M.K.: Microwave joining of high-purity alumina. In: Wachtman, J.B. (ed.) Proceedings of the 20th annual conference on composites, advanced ceramics, materials and structures A: ceramic engineering and science proceedings, vol. 17. John Wiley & Sons, Inc., Hoboken (2008)

    Google Scholar 

  10. 10.

    Cozzi, A.D., Clark,D.E., Porter, W.D., Cavin, O.B.: Potential interlayer materials for the microwave joining of alumina, In: J.B. Wachtman (ed.), Proceedings of the 18th annual conference on composites and advanced ceramic materials - B: ceramic engineering and science proceedings, vol. 15, John Wiley & Sons, Inc., Hoboken (2008)

  11. 11.

    Ahmad, I., Silberglitt, R., Tian, Y.L., Katz, J.D.: Microwave joining of SiC ceramics and composites. International World congress on microwave processing, Walt Disney Village (1997)

    Google Scholar 

  12. 12.

    Ahmad, I., Silberglitt,R., Black, W.M., Sa’Adaldin, H.S., Katz, J.D.: Microwave joining of silicon carbide using several different approaches, MRS Proc. 269B, 271-276 (1992)

  13. 13.

    Ahmad, I., Silberglitt, R.: Joining ceramics using microwave energy. MRS Proc. 314, 119–127 (1993)

    CAS  Article  Google Scholar 

  14. 14.

    Ahmad, I., Silberglitt, R., Shan, T.A.: Microwave-assisted pyrolysis of SiC and its application to joining. American Ceramic Society (ACS) annual meeting and exposition, Cincinnati (1995)

    Google Scholar 

  15. 15.

    Sato, T., Takahashi, N., Shimakage, K.: Microwave joining of alumina to magnesia. J. Ceram. Soc. Jpn. 104, 905–907 (1996)

    CAS  Article  Google Scholar 

  16. 16.

    Binner, J.G.P., Fernie, J.A., Whitaker, P.A.: An investigation into microwave bonding mechanisms via a study of silicon carbide and zirconia. J. Mater. Sci. 33, 3009–3015 (1998)

    CAS  Article  Google Scholar 

  17. 17.

    Binner, J.G.P., Fernie, J.A., Whitaker, P.A., Cross, T.E.: The effect of composition on the microwave bonding of alumina ceramics. J. Mater. Sci. 33, 3017–3029 (1998)

    CAS  Article  Google Scholar 

  18. 18.

    Al-Assafi, S., Clark, D.E.: Use of AlOOH gel in microwave joining of alumina. In: Wachtman, J.B. (ed.) Proceedings of the 16th annual conference on composites and advanced ceramic materials: ceramic engineering and science proceedings, vol. 13, pp. 1073–1080. Wiley, Hoboken (2008)

    Google Scholar 

  19. 19.

    Al-Assafi, S., Clark, D.E.: Microwave joining of ceramics: a study on joining alumina both directly and with alumina gel. MRS Proc. 269, 335–340 (1992)

    CAS  Article  Google Scholar 

  20. 20.

    Bykov, Y.V., Egorov, S.V., Eremeev, A.G., Rybakov, K.I., Zharova, N.A., Lobaev, M.A., Fliflet, A.W., Lewis, D., Imam, M.A., Rachkovskii, A.I.: Microwave joining of ZrO2 and Al2O3 ceramics via nanostructured interlayers. In: Tsakalakos, T., Ovid’ko, I.A., Vasudevan, A.K. (eds.) Nanostructures: Synthesis, Functional Properties and Applications, pp. 413–426. Springer Netherlands, Dordrecht (2003)

    Google Scholar 

  21. 21.

    Case, E.D., Crimp, M.A.: Joining of ceramic materials using spin-on interlayers. Adv. Eng. Mater. 3, 395–399 (2001)

    CAS  Article  Google Scholar 

  22. 22.

    Aravindan, S., Krishnamurthy, R.: Joining of ceramic composites by microwave heating. Mater. Lett. 38, 245–249 (1999)

    CAS  Article  Google Scholar 

  23. 23.

    Ahmed, A., Siores, E.: Microwave joining of 48% alumina–32% zirconia–20% silica ceramics. J. Mater. Process. Technol. 118, 88–94 (2001)

    CAS  Article  Google Scholar 

  24. 24.

    Ghosh, S., Chakraborty, R., Dandapat, N., Pal, K.S., Datta, S., Basu, D.: Characterization of alumina–alumina/graphite/monel superalloy brazed joints. Ceram. Int. 38, 663–670 (2012)

    CAS  Article  Google Scholar 

  25. 25.

    Shukla, M., Ghosh, S., Dandapat, N., Mandal, A.K., Balla, V.K.: Microwave-assisted brazing of alumina ceramics for electron tube applications. Bull. Mater. Sci. 39, 587–591 (2016)

    CAS  Article  Google Scholar 

  26. 26.

    Shukla, M., Ghosh, S., Dandapat, N., Mandal, A.K., Balla, V.K.: Fabrication of reliable joints of alumina ceramics by microwave-assisted reactive brazing technique. Mater. Trans. 57, 392–396 (2016)

    CAS  Article  Google Scholar 

  27. 27.

    Lin, K.-F., Lin, C.-C.: Interfacial reactions between Ti-6Al-4V alloy and zirconia mold during casting. J. Mater. Sci. 34, 5899–5906 (1999)

    CAS  Article  Google Scholar 

  28. 28.

    Xiong, H.P., Mao, W., Xie, Y.H., Guo, W.L., Li, X.H., Cheng, Y.Y.: Brazing of SiC to a wrought nickel-based superalloy using CoFeNi (Si, B) CrTi filler metal. Mater. Lett. 61, 4662–4665 (2007)

    CAS  Article  Google Scholar 

  29. 29.

    do Nascimento, R.M., Martinelli, A.E., Buschinelli, A.J.A.: Review article: recent advances in metal-ceramic brazing. Cermica. 49, 178–198 (2003)

    Article  Google Scholar 

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The authors acknowledge the financial support of Council of Scientific and Industrial Research (CSIR), India through network project (MTDDC-PSC0101).

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Correspondence to Sumana Ghosh.

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Shukla, M., Ghosh, S. Microwave-assisted alumina-zirconia brazed joint for microwave tubes. J Aust Ceram Soc 56, 873–883 (2020). https://doi.org/10.1007/s41779-019-00415-6

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  • Ceramics
  • Microwave brazing
  • Microhardness
  • Brazing strength
  • Scratch resistance
  • Microwave tube applications