Four sulphate-derived beryllia powders from three different commercial sources have been isostatically pressed and sintered. These powders showed significant variations in sintering behaviour which could be partially predicted by semi-empirical equations taking physical properties of the powder into account; the limitations of these equations are discussed. High strength is associated with high density, fine grained, and flaw-free sintered materials, and the four powders examined could be placed in a high or low strength category from a cursory glance at their microstructure. However, an overall correlation between purity and physical properties of powders, sinterability of compacts, and strength and microstructure of sintered compacts cannot be anticipated at the present stage of knowledge of sintering of ceramics
