Defect recovery processes in Cr-B binary and Cr-Al-B MAB phases: structure-dependent radiation tolerance

We have investigated the radiation tolerance of Cr-B binaries and Cr-Al-B ternary MAB phases using a combination of ab initio calculations and experiments. One key discovery is that Cr₃AlB₄ has excellent resistance to radiation-induced amorphization, and therefore it is a promising material for applications in extreme environments. We also demonstrate that both the type of B network and the presence of Al layer in the structure have important implications for defect kinetics. We find that the order of the tolerance to radiation-induced amorphization is, from high to low, CrB, Cr₃AlB₄, Cr₃B₄, Cr₄AlB₆, and Cr₂AlB₂ at 150 °C and 0.5 dpa, and Cr₃AlB₄, CrB, Cr₃B₄, Cr₄AlB₆, and Cr₂AlB₂ at 300 °C and 1.0 dpa. The results are explained in terms of defect properties determined from ab initio calculations.