Mechanism for Reducing Agglomeration in YAG Ceramic Powders Using Ammonium Sulfate Dispersant

Abstract

This study examines yttrium aluminum garnet (YAG) powders synthesized by chemical precipitation with and without ammonium sulfate dispersant. The influence of the dispersant on particle size distribution during calcination at various temperatures was evaluated. Scanning electron microscopy (SEM) revealed pronounced changes in the particle size and morphology of the powder, depending on the presence of the dispersant. Phase transformation kinetics were investigated using x-ray diffraction (XRD) and simultaneous thermal analysis (STA). The results support a new mechanism for reducing agglomeration in YAG powders through the addition of ammonium sulfate, which involves the formation of intermediate yttrium sulfate and oxysulfate phases that gradually decompose into the garnet phase.