TY  - JOUR
AU  - Wang, Weiming
AU  - Wang, Weide
AU  - Liu, Yiming
AU  - Zeng, Kuanhong
AU  - Mo, Yong
AU  - Ma, Qingsong
PY  - 2026
TI  - Synergistic improvement of flexural strength and fracture toughness in Si3N4 ceramics featuring high-entropy grain boundary phase
JO  - Journal of Advanced Ceramics
SN  - 2226-4108
SP  - 9221230
VL  - 15
IS  - 2
AB  - Developing silicon nitride (Si3N4) ceramics with concurrently enhanced flexural strength and fracture toughness presents significant challenges due to the critical dependence of these macroscopic properties on microstructure. This study produced high-performance Si3N4 ceramics by employing multiple rare earth (RE) oxides (RE2O3) as sintering additives to construct a multicomponent rare earth ion liquid phase via hot pressing sintering (HPS). The designed multicomponent RE-ion liquid phase reduces the shrinkage onset temperature while facilitating densification and α→β phase transformation. Synergistic effects among the multicomponent RE-ion liquid phase foster a distinct bimodal microstructure characterized by an optimized spatial distribution of refined matrix grains interlocked with elongated rod-like β-Si3N4 grains exhibiting elevated aspect ratios. Concurrently, the multicomponent RE-ion liquid phase crystallizes into a high-entropy (Gd0.2Y0.2Yb0.2Lu0.2Sc0.2)2Si2O7, enabling high crystallinity of the grain boundary phase in Si3N4 ceramics. Through concurrent optimization of microstructure and grain boundary phase properties in Si3N4 ceramics, synergistic enhancement in flexural strength (1322 MPa) and fracture toughness (10.88 MPa·m1/2) is achieved. Collectively, this high-entropy approach establishes a highly promising transformative strategy for developing high-performance structural ceramics.
UR  - https://doi.org/10.26599/JAC.2025.9221230
DO  - 10.26599/JAC.2025.9221230