Improving Al Wettability on B 4 C by Transition Metal Doping: a Combined DFT and Experiment Study

Abstract B 4 C/Al MMC is one of the most potential neutron-shielding materials. The poor wettability of B 4 C/Al interface damages the mechanical properties. To understand the alloying (or doping) effects in improving the wettability of B 4 C/Al interfaces, we investigated the Al(111)/AlB 2 (0001) and Al(111)/TiB 2 (0001) interfacial structures via a combined approach of experiment and DFT calculations. We find a larger work of adhesion ( W ad ) on the Al(111)/TiB 2 (0001) than the Al(111)/AlB 2 (0001) interfaces. The subsequently calculated partial density of states (PDOS) of doped-diborides show fewer anti-bonding states in Al(111)/TiB 2 (0001) than in Al(111)/AlB 2 (0001), which contribute to a stronger bonding between Ti-3d and B-2p states and lead to a higher W ad and better wetting. Furthermore, we predict improved wettability of Al/B 4 C by V-doping, because of the fewer anti-bonding states in vanadium-boron molecular orbitals. The same approach developed in this study may be applied for general design of alloy elements to improve the interfacial wetting of alloy-semiconductor systems.