Ultra-strong petalite glass-ceramics: Crystallization kinetics, thermal, optical, and mechanical properties

Abstract

Lithium aluminosilicate (LAS)-based glass-ceramics (GCs) were synthesized via a melt-quench process followed by controlled crystallization to obtain the petalite crystal phase. Crystallization kinetics were studied using the steady-state linear reaction model, non-linear kinetics, and model-free analysis. Isothermal predictions determined optimal crystallization rates for LAS-glass. Nucleation was controlled based on differential scanning calorimetry (DSC) analysis. X-ray diffraction (XRD) revealed petalite as the primary crystal phase, with minor phases including β-spodumene s.s., lithium aluminosilicate, and lithium metasilicate. FT-IR and Raman spectroscopy confirmed the bonding structures of petalite crystals. Scanning electron microscopy (FE-SEM) showed homogeneous nanocrystals with an average varying crystal size of 40–70 nm embedded within the glass phase. The coefficient of thermal expansion (CTE) of the glass-ceramics decreased to 7.2 × 10⁻⁶/ °C post-ceramization. After heat treatment at 650 °C for 10 h, the GCs exhibited 88 % optical transparency at 589 nm, with remarkable mechanical properties: Vickers hardness of 7.88 GPa, elastic modulus of 95 GPa, and fracture toughness of 4.00 MPa·m⁰^.⁵. These properties suggest significant potential for applications in electronic displays, transparent armor, and satellites.