Rapid fabrication of high-density YAG ceramics via spark plasma sintering of mesoporous YAG powder

Yttrium aluminum garnet (YAG) has garnered extensive attention and research interest as an ideal laser host material due to its excellent optical properties, mechanical strength, and stable physicochemical characteristics. This study successfully fabricated highly dense (99.8% relative density) YAG ceramics via high-specific-surface-area mesoporous YAG powders combined with spark plasma sintering (SPS) at 1400°C under 60 MPa, with a dwell time of only 3 min. The as-fabricated dense YAG ceramics exhibited excellent mechanical properties, including a Vickers hardness (HV) of 15.02 GPa and a fracture toughness of 2.3 MPa·m 1 / 2 . This research reveals the critical role of highly sinter-active mesoporous YAG powders in the low-temperature preparation of high-density YAG ceramics, while also providing a novel and important strategy for rapidly producing high-performance fine YAG ceramics at low sintering temperatures.