Structural-functional integrated TiB2/Al-Mg-Gd composite with efficient neutron shielding phases and superior mechanical properties

The structural-functional integrated TiB2/Al-Mg-Gd composite was fabricated by the powder metallurgy-based methods, including atomized composite powder fabrication, spark plasma sintering and hot extrusion techniques. In this manner, the atomization process effectively refined Gd-contained phases and dispersed TiB2 particles in composite powders. Such refinement was inherited to the as-extruded composite. In detail, the finer Gd-contained phase was confirmed to be tau(MgNi2-type) Laves phase. Functionally, the composite had high thermal neutron shielding efficiency (99%), which was higher than the published results for neutron shielding materials. This phenomenon was analyzed by the Shmakov-Yamamoto model. The theoretical simulation showed that the refinement of tau phases played a key role in improving the neutron shielding property, which agreed well with experiment results. Structurally, the yield strength, tensile strength and elongation of the TiB2/Al-Mg-Gd composite were 353 +/- 5 MPa, 464 +/- 6 MPa and 15.6 +/- 0.4%, respectively. Such mechanical properties were considerably higher over available neutron shielding materials. Regarding the improved yield strength, both solution strengthening effect and grain refinement strengthening effect were quantitatively analyzed to be the major strengthen contributors. Finally, this novel composite can be a promising candidate for neutron shielding materials in future.

Automated summary

A structural-functional integrated TiB2/Al-Mg-Gd composite with high thermal neutron shielding efficiency (99%) and excellent mechanical properties was fabricated using powder metallurgy-based methods. The refinement of Gd-contained phase in the composite played a key role in improving the neutron shielding property, which was supported by theoretical simulations and experimental results. This novel composite has the potential to be a promising candidate for neutron shielding materials in the future.