Paper Titles
Hydrothermal Synthesis of Bi1.5ZnNb1.5O7 Nanopowders
p.495
Study of the Preparation Technology and Properties of BaBi4Ti4O15 Ceramics
p.499
Edge Effects in Sliding Wear Behavior of ZrO2-WC Composites and WC-Co Cemented Carbides
p.503
Study of Water-Debinding for Ceramic Parts by Injection Molding
p.507
Millimeter-Wave Assisted Sintering of Polycrystalline Yttria for Laser Host Material
p.511
Barium Titanate Nanopowders Prepared from the Modified Oxalate Co-Precipitation Method
p.515
Fabrication of Bi2-xSbxTe3 (x=0-1.5) Thick Film by Centrifugal Deposition
p.519
Synthesis of Ultra-Fine and High-Pure Zirconium Diboride Powders Using Solution-Based Processing
p.523
Simultaneous Synthesis and Consolidation of W-Added ZrB2 by Pulsed Electric Current Pressure Sintering and their Mechanical Properties
p.527

Millimeter-Wave Assisted Sintering of Polycrystalline Yttria for Laser Host Material

Article Preview

Abstract:

We report an investigation of millimeter-wave processing of yttria for fabrication of transparent, high-strength polycrystalline laser hosts for high energy laser (HEL) applications. Advantages of polycrystalline, compared to single-crystal laser host materials, include lower processing temperature, higher gain with flexibility of higher dopant concentrations, cheaper fabrication, and larger-size devices. Millimeter-wave processing is an alternative method to solve the problems of both conventional vacuum and low-frequency microwave sintering, such as low heating rate, poor coupling and thermal gradients. A major component of the millimeter-wave processing facility is a 20-kW, continuous-wave, 83-GHz gyrotron oscillator. Yttria has been successfully sintered with millimeter-wave beams with up to 99% theoretical density. A partially transparent yttria sample has also been achieved using the millimeter-wave sintering process [1]. Several factors impact the quality of the sintered material including the presence of agglomerates, impurities, processing atmosphere, sintering aids, and thermal gradients. Efforts to improve the transparency will be discussed.

You might also be interested in these eBooks
PRICM 6 View Preview

Info:

Periodical:

Materials Science Forum (Volumes 561-565)

Pages:

511-514

DOI:

https://doi.org/10.4028/www.scientific.net/MSF.561-565.511

Citation:

Cite this paper

Online since:

October 2007

Authors:

Melissa K. Hornstein, Ralph W. Bruce, Arne W. Fliflet, Steven H. Gold, Manfred Kahn, M. Ashraf Imam

Keywords:

Ceramic, Gyrotron, Laser, Laser Host, Millimeter-wave Processing, Polycrystalline

Export:

RIS, BibTeX

Price:

Permissions CCC:

Request Permissions

Permissions PLS:

Request Permissions

Сopyright:

© 2007 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

References

[1] M. Lombardi, A. W. Fliflet, et al., Millimeter-wave sintering of polycrystalline ceramic laser materials, IRMMW-THz 2005, (2005).

Google Scholar

[2] A. Ikesue and I. Furusato, Fabrication of polycrystalline, transparent YAG ceramics by a solid-state reaction method, J. Am. Ceram. Soc., 78 225-28 (1995).

DOI: 10.1002/chin.199617258

Google Scholar

[3] J. Kong, D. Y. Tang, B. Zhao, J. Lu, K. Ueda, H. Yagi and T. Yanagitani, 9. 2-W diode- end-pumped Yb: Y2O3 ceramic laser, Appl. Phys. Lett. 86, 161116 (2005).

DOI: 10.1063/1.1914958

Google Scholar

[4] D. Lewis, M. A. Imam, et al., Material processing with a high frequency millimeter-wave source, Mat. Manuf. Proc. 18, 151-167 (2003).

Google Scholar

[5] R.W. Bruce, et al., Joining of ceramic tubes using a high-power 83-GHz Millimeter-wave beam, IEEE Trans. Plasma Sci. 33, 668-678, (2005).

DOI: 10.1109/tps.2005.844509

Google Scholar

[6] K. G. Ayappa, H. T. Davis, E. A. Davis, and J. Gordon, Analysis of Microwave Heating of Materials with Temperature-Dependent Properties, AIChE Journal 37, 313-322, (1991).

DOI: 10.1002/aic.690370302

Google Scholar

[7] A. Ikesue and K. Yoshida, Influence of pore volume on laser performance of Nd: YAG ceramics, J. Mat. Sci. 34, 1189-1195, (1999).

Google Scholar