Elemental segregation inhibits hydrogen embrittlement in aluminium alloys

In this study, we performed first-principles calculations to determine the effects of four metallic solutes (Y, Zr, Mg,and Zn) on the hydrogen embrittlement (HE) of aluminum alloys with the Σ5(210) grain boundary (GB). Thesegregation energy, associated segregation concentration, and binding energy of these solutes were examined toidentify their states. Moreover, the ability of the aforementioned solutes to inhibit or promote HE in the aforementioned alloys through GB energy, free surface energy, and adhesion was investigated. The Griffith andRice–Wang–Scheiber models were used to determine the effect of nonequilibrium concentration on adhesion.Tensile tests were performed using the uniaxial strain loading method to determine the ultimate tensile strengthand GB elongation of the considered alloys. The mechanism of HE inhibition by the four solutes was investigatedby examining the charge density, Bader charge, and crystal orbital Hamiltonian population of the alloys. Finally,the calculation results of this study were validated through experiments.