Density gradients and sintered dimensional tolerance in compacts formed from spray-dried alumina

This study proves that initial density gradients have lasting detrimental e ffects on final dimensional tolerances. X-ray computed tomography has been used to quantify changes in density following sintering; associated dimensi onal changes have been monitored using a laser micrometer. Nonuniformities present in the green state are still present at an overall relative density of similar to 73%; in fact, these nonuniformities are exaggerated. Major l osses of dimensional tolerance are triggered by the initial density gradien ts.