Nanopowder synthesis and pressureless sintering of nanocrystalline Y3Al5O12 ceramics

Abstract

The exploration of sintering dynamics in systems involving oxide nanoparticles is vital for the production of nanocrystalline oxide ceramics. Until now, a thorough investigation into the sintering kinetics of well-dispersed, fine-grained yttrium aluminum garnet yttrium aluminum garnet (Y₃Al₅O₁₂; YAG) nanoparticles has been lacking. In this study, we delve into the sintering kinetics of uniformly dispersed, equiaxed YAG nanoparticles, which possess an average diameter of 9 nm and span a size range from 3 to 39 nm. We have successfully fabricated dense YAG ceramics with an average grain size of 86 nm through a pressureless sintering process in air atmosphere at a mere 1200°C for a duration of 2 h. This sintering temperature marks the lowest recorded for the pressureless sintering of YAG ceramics. The resulting nearly fully dense YAG nanocrystalline ceramics showcase the finest grain size achieved to date via pressureless sintering techniques, aligning with our efforts to refine grain size and reduce sintering temperatures in advanced ceramic materials.