Ball-milling properties and sintering behavior of Al-based Gd2O3–W shielding materials used in spent-fuel storage

To overcome the disadvantages of commercial neutron absorbers used for spent-fuel storage, novel Al-based Gd2O3–W composites were designed by calculating the neutron absorption and γ-ray transmission and synthesized via ball milling, cold isostatic pressing, and sintering. During the ball milling, the cubic Gd2O3 was partially transformed into monoclinic Gd2O3, and new Al3Gd and Gd3Al5O12 phases were formed. The sintering induced chemical reactions that formed Gd3Al5O12, Al3Gd, and Al12W phases. Nanoparticles with sizes of 100–300 nm were uniformly distributed in the sintered bulk materials. Moreover, with increasing sintering time, sintering temperature, and W content, the microhardness of the Al-based Gd2O3–W metal matrix composites (MMCs) increased. The compressive strength of the Al-based Gd2O3–W MMCs increased with W content, in contrast to the thermal expansion coefficient. Overall, the properties of the synthesized composites were better than those of the reference Al–B4C. [Display omitted] •Novel MMCs that shield neutron and γ-ray simultaneously are synthesized.•Neutron and γ-ray shielding effects of Al-based Gd2O3-W MMCs are calculated.•Monoclinic Gd2O3, amorphous, Al3Gd and Gd3Al5O12 are produced during ball milling.•The chemical reactions are promoted by sintering and nanoparticles are distributed uniformly.•Relationships between mechanical/thermal properties and preparation parameters are analyzed.