Transactions of the INDIAN CERAMIC SOCIETY Vol. 26 1967
Sintering of Beryllia-Part II : Hot Pressing
of Beryllia Powders of Different Origins
and Thermal Treatments
V. K. MOORTHY, G. T. KAMATH AND J. K. BAHL
Pages : 19-24
DOI : 10.1080/0371750X.1967.10855581
Abstract
Beryllia of high density and controlled microstructure is necessary for application
as moderator in various reactor systems. Normally, high density beryllia is prepared by
hot pressing at temperatures beyond 1700°C. The sintering behaviour, either in cold
pressing and sintering or in hot pressing is influenced by the powder characteristics of
the raw material. In this investigation, the sintering behaviour during hot pressing of
bery!lia powders of divergent characteristics (i.e. prepared from different compounds
and subjected to different calcination treatments) has been studied. It was found that
powders derived from the sulphate by calcination at 750°C, attained a densification of
over 99% theoretical density (2.99 gmfcc; theoretical density 3.01 gmfcc) at a temperature
of 1400°C. Attainment of densification at lower temperatures results in
little grain development and thus offers the chance to obtain samples sintered to a high
density and controlled microstructure. Attempts are made to relate the densification
behaviour and microstructure development to the characteristics of the raw powders.
