Manipulation of mechanical properties of a promising radiation shielding metal-ceramic composite using electropulsing

Abstract

Radiation shielding materials with integrated exceptional shielding capacities and robust mechanical properties have critical applications in nuclear industries. A promising radiation shielding metal-ceramic MAB phase material, containing tungsten (M = W), aluminium (A = Al) and boron (B), exhibits comprehensive neutron and gamma ray shielding capacities but suffers from strong brittleness. In this study, a novel strategy using electropulsing was employed to toughen this material. It was demonstrated that the flexural strength and displacement of electropulsed materials were significantly enhanced by up to 92 % and 640 %, respectively. It was revealed that electropulsing activates the debonding of Al atoms in the MAB lattice, which results in the healing of existing holes within materials. Interestingly, electropulsing induced the formation of mixed crystalline and amorphous Al structures that wrapped the WAlB and WB phases. The large capacity of amorphous Al accommodating shear strains renders the enhanced flexural properties while maintaining the shielding capacity of materials after electropulsing. The findings may remove one of the bottlenecks for the industrial application of these materials, and provide a promising approach for toughening other similar ceramics with intrinsic brittle characters.