The effect of calcination and ball-milling on the properties of Ni·Zn-and Mn·Zn-ferrite powders was studied and the results are discussed on the basis of theoretical considerations on tap density. It is shown that the ball-milling has two different effects on the powder properties depending on whether the temperature of calcination is above or below the recrystallization temperature. It is found that striking correlations exist among these properties, and that the tap density is one of the most useful and convenient parameters not only for the evaluation of powder history but also for the prediction of sintering performance.
