Impurities and their effects in nuclear-grade beryllia powders.

Abstract

The criteria for sinterability in high purity beryllia powders are discussed. Of common impurities in less pure powders, silicon, aluminium, calcium, magnesium andiron are considered to have the major effects on sinterability. Of these, Si and Al have detrimental effects, and Ca, Mg and Fe beneficial effects. It is suggested that for an impure powder to be sinterable, the combined (Si + Al) content should be no higher than the combined (Ca + Mg + Fe) content, both expressed in p.p.m.