Paper Title:
Characterization of Particle Alignment in Pre-Sintered Alumina Body Using Birefringence Imaging Microscopy
  Abstract

The packing structure in green alumina bodies has been studied using thin sections of prefired bodies impregnated with refractive-index liquid examined with an automatic, polarizedlight microscope equipped with liquid-crystal adjustable quarter-wave plate and analyzer, and circularly polarized light. The combined intrinsic birefringence (caused by the anisotropy of the hexagonal symmetry of the alumina particles) and form birefringence (due to packing of the slightly elongated particles oriented in the green structure), can be quantified on a small scale. Birefringence values and slow-vibration directions are mapped for the anisotropic fine particles and agglomerates circumferentially or radially aligned in the structure. For some pre-sintered bodies, the interference pattern shows three radial dark brushes with relatively low birefringence, coming from the spider in the extruder. Slow-axis distribution shows random particle orientation in the spider region. The birefringence pattern often indicates a relatively high degree of circumferential alignment in the surface area where frictional force is present during forming. A uniform distribution of the birefringence represents a consistent green structure. The improved procedure for characterization of prefired body provides considerable insight to the optical crystallography of powder/particle arrangement in pre-sintered ceramic body and the relationship of the particle alignment with respect to flow and forming.

  Info
Periodical
Edited by
P. VINCENZINI
Pages
486-490
DOI
10.4028/www.scientific.net/AST.45.486
Citation
G. C. Wei, "Characterization of Particle Alignment in Pre-Sintered Alumina Body Using Birefringence Imaging Microscopy", Advances in Science and Technology, Vol. 45, pp. 486-490, 2006
Online since
October 2006
Authors
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Rak Joo Sung, Dong Suk Kim, Su Ah Ji, Jeong Sik Park, Sang Woo Kim
Abstract:Density, purity, grain, and grain size distribution are the key factors that influence the transparency of an optical ceramics. To achieve...
822
Authors: Won Seung Cho, Yeon Chul Yoo, Chin Myung Whang, Nam Hee Cho, Woon Suk Hwang, Jun Gyu Kim, Young Jae Kwon
Abstract:Porous alumina bodies were successfully prepared by spark plasma sintering of alumina powders with different amounts of graphite, and by...
1056
Authors: R. Svinka, V. Svinka, G. Bula, T. Juettner, E. Palcevskis
Abstract:Light weight materials are produced according to the aerated concrete technology using slurries. In concentrated suspensions pore formation...
2266
Authors: Shunkichi Ueno, Li Ming Lin, Hideo Nakajima
Abstract:A porous alumina with cylindrical pores was fabricated by unidirectional solidification under hydrogen gas flow (0.1 MPa) using alumina feed...
313
Authors: Ian P. Shapiro, Xiao Feng Zhao, Hui Xu, Ping Xiao
Abstract:The constrained sintering behavior of yttria stabilized zirconia coatings containing 1 wt. % alumina produced using electrophoretic...
177