Instability of Cylindrical Voids in Alumina
Author:
- 1 May 1978
- journal article
- Published by Wiley in Journal of the American Ceramic Society
- Vol. 61 (5-6) , 191-195
Abstract
It is shown from experimental observation that cylindrical voids in polycrystalline alumina are unstable. When isothermally annealed, they undergo various configurational changes, in accordance with the theoretical prediction, prior to an ultimate breakup into rows of spherical voids. The breakup occurs by ovulation, if the aspect ratio is appropriate. If the required aspect ratio is not met, cylindrical voids are directly transformed into spherical voids by spheroidization. The predominant mechanism for void breakup on thermal anneal confirms a model for surface‐diffusion‐control material transport. The estimated surface‐diffusion coefficients at the experimental annealing temperatures agree, within an order of magnitude, with the values reported in the literature.Keywords
This publication has 16 references indexed in Scilit:
- On the spheroidization of rod-shaped particles of finite lengthJournal of Materials Science, 1976
- On the spheroidization of rod-shaped particles of finite lengthJournal of Materials Science, 1976
- Surface Diffusion of Single‐Crystal Al 2 O 3 by Scratch‐Smoothing MethodJournal of the American Ceramic Society, 1975
- In-situ observations of the annealing of liquid lead inclusions entrained in an aluminium matrixJournal of Materials Science, 1974
- The stability of sapphire whiskers in nickel at elevated temperaturesJournal of Materials Science, 1973
- The kinetics of spheroidization of lead inclusions in aluminiumPhilosophical Magazine, 1973
- Kinetics and mechanisms of pore growth in MgOJournal of Materials Science, 1971
- Part I. IntroductionJournal of Nuclear Materials, 1969
- Kinetics of diffusional motion of pores in solidsJournal of Nuclear Materials, 1969
- Relative Energies of Tilt Boundaries in Aluminum OxideJournal of the American Ceramic Society, 1968