Innovative pathways to high-performance glass ceramics: Harnessing nature's treasures with chromium and zirconium nucleation catalysts

Abstract

This study explores the novel production of high-performance glass ceramics (GCs) by harnessing readily available and cost-effective raw materials schist, dolomite, and magnesite for the first time. The nominal composition for the base glass, G(30), was designed based on the eutectic composition of the diopside-anorthite ratio with 30% enstatite content within the quaternary CaO-MgO-Al2O3-SiO2 system. To enhance nucleation, chromium (Cr2O3) and zirconium (ZrO2) oxide were separately introduced into the base glass batch in two ratios (0.5% and 1%), producing four additional batches-Cr(0.5), Cr(1), Zr(0.5), and Zr(1), orderly. All these batches were melted at temperatures ranging from 1450 °C to 1550 °C then cast into glass discs and rods. Double-stage heat treatment schedule, 750 °C /2 h followed by 950 °C and 1050 °C/1 h separately, was employed to induce the transformation of prepared glass into GCs. X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques were applied to orderly investigate the developed crystalline phases and the prevailing micro-structures of the prepared GCs. The glass ceramic with the highest Cr2O3 ratio, Cy(1) which was treated at 1050 °C/1 h, displayed the most adequate microstructure and minimal pore formation in comparison with other GCs. As well, the favorable physicochemical properties, Vickers microhardness (6.43 GPa), low thermal expansion coefficient (0.171 ×10 −6 °C−1) at 29–100 °C, and the exceptional resistance for acid and alkali corrosion (95%), nominate such GS sample, Cy(1), for several architectural applications.