Radiation shielding and mechanical properties of mullite-zirconia composites fabricated from investment-casting shell waste

Abstract

Low-cost zirconia-toughened mullite composites were prepared from investment casting shell waste and alumina. The influence of sintering temperature on the composites\" properties, including crystalline phase composition, microstructure, degrees of densification, mechanical properties, and radiation shielding characteristics, was investigated. The results show that the higher the sintering temperature, the higher the degree of densification is, improving the mechanical and radiation shielding properties of prepared composites. The mullite-zirconia composite sintered at 1600 °C presents a good mechanical strength, with flexural and compressive strength values of 190 and 308 MPa, respectively. These values are comparable to or even better than mullite ceramics prepared from other waste materials. Furthermore, the composites\" gamma-ray and neutron attenuation characteristics suggest that they can be promising as radiation shields.