Utilization of investment casting shell waste in the production of cordierite-mullite-zircon composites for radiation shielding: The influence of La2O3 additive

Cordierite-mullite-zircon ceramic composites were produced via reaction sintering of investment casting shell waste, Al2O3, and MgO at 1350 °C. The influence of La2O3 addition on the crystalline phase composition, microstructure, densification behavior, mechanical strength, and radiation shielding capabilities of the cordierite-mullite-zircon composites has been investigated. The X-ray diffraction (XRD) analysis confirmed the successful synthesis of cordierite-mullite-zircon composites with up to 5 wt.% La2O3 additive content. However, a higher La2O3 content, exceeding 7 wt.% resulted in cordierite decomposition. Furthermore, the addition of La2O3 significantly enhanced the densification behavior and microstructural development, leading to improved flexural strength and enhanced shielding against fast neutron and gamma radiation. This research suggests the potential of the fabricated ceramic composites derived from investment casting shell waste for applications in radiation shielding.