Low‐temperature fabrication of transparent mullite glass‐ceramics from sodalite zeolite via spark plasma sintering

Abstract Transparent aluminosilicate glass‐ceramics with exceptional mechanical properties are highly desirable for advanced optical applications but are often hampered by high processing temperatures and limited toughness. Herein, we report a novel low‐temperature strategy to fabricate highly transparent and mechanically robust glass‐ceramics using sodalite (SOD) zeolite as a precursor via spark plasma sintering (SPS). The controlled thermal treatment enables the evolution from a transparent SOD glass‐ceramic to a composite containing rod‐like mullite crystals. The sample sintered at 780℃ exhibits a transmittance of over 82% at 380–780 nm. The precipitation of mullite significantly enhances mechanical performance, yielding a Vickers hardness of up to 8 GPa. An optimal fracture toughness of 1.5 MPa·m 1/2 is achieved at 830℃, attributed to a synergistic toughening mechanism involving crack deflection and bridging by the interlocking microstructure of equiaxed SOD and anisotropic mullite grains. This study demonstrates the immense potential of zeolite precursors coupled with SPS for designing and manufacturing high‐performance transparent glass‐ceramics with tailored microstructures and properties.