Recent Advances in Microwave and Millimeter-Wave Processing of Materials


Article Preview

We are using 2.45 GHz (S-Band) microwave systems and an 83-GHz, gytrotron-based, millimeter-wave beam system in material processing and other areas. We use one 2.45 GHz system in preparation of nanophase metals, metal mixtures and metal oxides, via the patented continuous microwave polyol process, with potential for large scale, low cost production. Of interest are precious metals, mixtures of magnetic and nonmagnetic metals, and mixed metal oxides for ceramic precursors. The other S-Band systems are used to develop repair techniques for ceramic matrix composites where the repairs are heated to 200-1000°C. A portable, battery-powered system is being developed for field repairs, and promises to be much more practical than alternative approaches (e.g., heating blankets). The 83-GHz system is being used in rapid sintering of polycrystalline ceramic materials intended for use in high power solid state lasers, where the requirement if for sintering to transparency with high optical quality and good lasing efficiency. Transparent Yb-doped yttria has been produced with hybrid conventional/millimeter-wave sintering of nanophase powders, as well as theoretically dense YAG. Another application for the millimeterwave beam system is in consolidation and bonding of hard coatings to light alloys, such as SiC on titanium, where the beam system allows heating of the coating to very high temperatures without overheating the metallic substrate. Finally, the millimeter-wave system is being used in the development of millimeter-wave plasma-assisted diamond deposition, where the quasi-optical system has significant advantages over conventional microwave plasma-assisted diamond deposition. Results for these various areas will be presented and discussed.



Materials Science Forum (Volumes 539-543)

Main Theme:

Edited by:

T. Chandra, K. Tsuzaki, M. Militzer , C. Ravindran




D. Lewis III et al., "Recent Advances in Microwave and Millimeter-Wave Processing of Materials", Materials Science Forum, Vols. 539-543, pp. 3249-3254, 2007

Online since:

March 2007




[1] D. Lewis III, L. K. Kurihara, R. W. Bruce, R. L. Bruce, A. W. Fliflet and S. H. Gold, Continuous Production of Nanophase Metals, Metal Oxides and Mixtures Using a Microwave-Driven Polyol Process, 294-301 in Bridging Science, Technology and Applications, Proc. of the 4th World Congress on Microwave and Radio Frequency Applications, Ed. R. Schulz and D. Folz, Microwave Working Group, Arnold, MD (2005).


[2] R. W. Bruce, R. L. Bruce, D. Lewis III, S. H. Gold, M. Kahn, A. K. Kinkead and A. W. Fliflet, Reactive Oxide Braze Joining of Ceramic Tubes with a High-Power 83-GHz Millimeter-Wave Beam System, Ibid 133-141.


[3] D. Lewis, R. W. Bruce, A. W. Fliflet, S. H. Gold, A. K. Kinkead, M. Lombardi, R. L. Bruce and G. M. Briggs, Microwave Curing of Ceramic Composite Repair Materials, " to be published in Proceedings of the 29 th Annual Conference on Advanced Ceramics and Composites, The American Ceramic Society Inc., Westerville, OH, 2005. 4. L. K. Kurihara, R. W. Bruce, A. W. Fliflet, and D. Lewis, "Processing of Nanocrystalline Metallic Powders and Coatings Using the Polyol Process, U. S. Patent No. 6, 746, 510 (2004).


[5] D. Lewis, A. W. Fliflet, R. W. Bruce, Removing Radar Absorbing Coatings, U. S. Patent No. 6, 802, 907 (2004).

[6] D. Lewis, R. W. Bruce, A. W. Fliflet, S. H. Gold, and L. K. Kurihara, "Microwave-Assisted Continuous Synthesis of Nanocrystalline Powders and Coatings Using the Polyol Process, U. S. Patent No. 6, 833, 019 (2004).

[7] R. W. Bruce, R. L. Bruce, A. W. Fliflet, D. Lewis, M. Kahn, S. H. Gold, A. K. Kinkead, M. A. Imam, Joining of Ceramic Tubes Using a High-Power 83!GHz Millimeter-Wave Beam, IEEE Trans. on Plasma Science, Vol. 33, No. 2, 668-678 (2005).


[8] R. Peelamedu, R. Roy, L. Hurtt, D. Agrawal, A. W. Fliflet, D. Lewis III, R. W. Bruce, Phase formation and decrystallization effects on BaCO3 + 4Fe3O4 mixtures; a comparison of 83!GHz, multimode millimeter-wave and 2. 45!GHz single mode microwave H-field processing, Materials Chemistry and Physics (2004).


[9] Y. V. Bykov, S. V. Egorov, A. G. Eremeev, K. I. Rybakov, N. A. Zharova, M. A. Lobaev, A. W. Fliflet, D. Lewis, M. A. Imam, A. I. Rachkovskii, Microwave joining of ZrO2 and Al2O3 ceramics via nanostructured interlayers, " in Synthesis, Functional Properties and Applications of Nanostructures, NATO Science Series II: Mathematics, Physics and Chemistry: Vol. 28, ed. T. Tsalakos, I. A. Ovid, ko and A. K. Vasudevan, pp.413-426 (2004).


[10] D. Lewis, L. K. Kurihara, R. W. Bruce, A. W. Fliflet and A. M. Jung, Millimeter-Wave Beam Processing and Production of Ceramic and Metal Materials, in Defense Applications of Nanomaterials, ACS Symp. Series No. 891, ed. A. W. Miziolek, S. P. Karna, M. Mauro and R. A. Vaia, (2004).


[11] D. Lewis III, R. W. Bruce, M. A. Imam, A. W. Fliflet, Joining of materials with millimeter-wave beam source, Science and Technology of Welding and Joining, Vol. 9, No. 4, (2004).


[12] M.A. Imam, David Lewis, III, Ralph W. Bruce, A. W. Fliflet and Lynn K. Kurihara, Processing of Advanced Materials with a High Frequency, Millimeter-Wave Beam Source and Other Microwave Systems, Materials Science Forum, Vols. 426-432, 4111-4116 (2003).


[13] D. Lewis, M. A. Imam, R. W. Bruce, L. Kurihara, A. W. Fliflet and S. H. Gold, Production of Nanophase Metals via the Continuous Microwave Polyol Process, 157-167 in Powder Materials: Current Research and Industrial Practices III, ed. F. D. S. Marquis, TMS (2003).


[14] D. Lewis, M. A. Imam, L. K. Kurihara, A. W. Fliflet, S. Gold, R. W. Bruce et al., Material Processing with a High Frequency Millimeter-Wave Source, Materials and Manufacturing Processes, Vol. 18, No. 2, pp.151-167, (2003).


[15] David Lewis III, Arne W. Fliflet, Ralph W. Bruce, Manfred Kahn and M.A. Imam, Use of a High Frequency, Millimeter-Wave system in Joining High Temperature Ceramics, Proceedings 13th IFHTSE/ASM Surface Engineering Congress, ASM, (2002).

[16] L. K. Kurihara, D. Lewis, A. M. Jung, A. W. Fliflet and R. W. Bruce, "Millimeter-Wave Driven Polyol Processing of Nanocrystalline Metals, Proceedings MRS, Vol. 634, Structure and Mechanical Properties of Nanophase Materials, ed. D. Farkas et al. (2001).


[17] W. Fliflet, R. W. Bruce, R. P. Fischer, D. Lewis, L. K. Kurihara and B. A. Bender, A Study of Millimeter-Wave Sintering of Fine-Grained Alumina Compacts, " IEEE Trans. Plasma Sci., vol. 28, No. 3, pp.924-935, (2000).


[18] R. W. Bruce, A. W. Fliflet, R. P. Fischer, D. Lewis III, B. Bender and L. K. Kurihara, Millimeter-wave processing of alumina compacts, Ceram. Trans. Vol. 80, pp.287-294, (1997).

[19] R. F. Hubbard, A. W. Fliflet, D. Lewis, J. Bowles and D. Kidwell, Long Range Active Thermal Imaging Using a Microwave or Millimeter-Wave Beam, U.S. Patent Application filed 21 September (2005).

[20] R. F. Hubbard et al., Active Thermal Imaging Using a Millimeter-Wave Source (ATIMS), " presented at DEPS 8 th Ann Directed Energy Symp., Lihue, Hawaii, 14-18 Nov (2005).