"

Cookies ussage consent

Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our site without changing the browser settings you grant us permission to store that information on your device.

I agree, do not show this message again.

PACKING MODELS OF YTTRIUM DOPED aaaa - AL2O3: STUDY OF POROSITY

N. Popescu-Pogrion1,* , R. Bercia2, M. Tirnovan2

Affiliation

  1. National Institute R&D of Materials Physics, 77125 Bucharest-Magurele, Romania
  2. University POLITEHNICA Bucharest, 313 Spl. Independentei, Bucharest, Rromania

Abstract

Dopant yttrium at 150 p.p.m. level ( Y to Al atomic ratio) in ultra –high purity polycrystalline alumina has been found to be, together with the coefficient of porosity, the reason of grain growth : with abnormal grain growth (AGG) or with uniform grains. The powder, green bodies and sintering samples were studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and packing models. In this paper we studied by mathematical modeling the correlation between structure of powder and green bodies in correlation with the porosity in sintering compacts. A formula, which describes the packing of the spherical – cylindrical homogeneous particles, has been obtained. The porosity of the low Y doped a- Al2O3 was investigated..

Keywords

Porosity, a- Al2O3, Packing modelling, Electron microscopy.

Submitted at: April 20, 2004
Accepted at: June 22, 2004

Citation

N. Popescu-Pogrion, R. Bercia, M. Tirnovan, PACKING MODELS OF YTTRIUM DOPED aaaa - AL2O3: STUDY OF POROSITY, Journal of Optoelectronics and Advanced Materials Vol. 6, Iss. 3, pp. 1071-1075 (2004)