Microstructure evolution and strengthening mechanism of Gd2O3/6061Al neutron shielding composite during rolling

10 wt%Gd2O3/6061Al neutron shielding composites were successful prepared by spark plasma sintering and hot rolling, and its microstructure evolution and strengthening mechanisms during hot rolling were studied. Gd2O3 particles distributed along matrix boundaries to form a continuous polygon net structure at sintered state. With the increase of deformation, Gd2O3 particles gradually distributed uniformly, and the connectivity of 6061Al was greatly improved. The mechanical properties of the materials have been improved due to the double reinforcement effect from the grain boundary enhancement of micrometer particles and the grain internal enhancement of nanoparticles. Gd2O3 particles were found to be able to restrain the grain grows, reduce the preferential orientation and stimulate dynamic recrystallization. The second phase in the 10 wt%Gd2O3/6061Al composite was mainly Gd3Al5O12, and there was no phase transition occurs during hot rolling deformation process. The composite strengthening mechanisms are primarily attributed to Orowan strengthening. The fracture mechanism of Gd2O3/6061Al composite has changed from brittle to ductile fracture after hot rolling. •10 wt%Gd2O3/6061Al composites were prepared by spark plasma sintering and hot rolling.•With the increase of the rolling deformation, the plasticity deformation ability of the composite was increased.•The second phase in the 10 wt%Gd2O3/6061Al composite was mainly Gd3Al5O12, and there was no phase transition occurs during hot rolling deformation process.•The composite strengthening mechanism primarily attributed to Orowan strengthening, and the fracture mechanism of composite has changed from brittle fracture to ductile fracture.