Investigation of the Processes Involved in the Formation of Pyroxene Materials during Solar Melting in a Large Solar Furnace

The study investigates the influence of the parameters of concentrated light radiation (CLR) and the melt-cooling conditions on the structure formation, phase composition, and properties of pyroxene glass-ceramics. It is established that quenching the melt in water results in the formation of an amorphous glass, whereas reducing the cooling rate (~100 °C/s) leads to partial crystallization with the formation of diopside and augite phases. An increase in CLR flux density from 100 to 300 W/cm² promotes a higher degree of crystallinity, transitioning from a diopside– augite mixture to a monomineralic diopside–hedenbergite phase Ca(Fe,Mg)Si₂O₆. Increasing the flux density and the melt holding time is accompanied by an increase in apparent density (from ~2.70 to ~2.90 g/cm³) and a decrease in abrasion loss (from ~0.018 to ~0.008 g/cm³), indicating enhanced densification and wear resistance of the material. Optimal CLR conditions (≈300 W/cm², ~10³ °C/s) ensure the formation of a dense, homogeneous microstructure with low water absorption (0.02 %), high wear resistance (0.006 g/cm²), and a flexural strength of ≈145 MPa. The obtained results confirm the promise of pyroxene glass-ceramics for applications requiring thermally stable and wear-resistant materials.