Mechanisms of hydrogen embrittlement in high-strength aluminum alloys containing coherent or incoherent dispersoids

Abstract This study investigated the hydrogen embrittlement of a high strength Zr or Cr- added aluminum alloy specimens containing coherent Al3Zr or incoherent Al18Mg2Cr3 dispersoids, respectively. The elastic interaction between coherency strain and hydrogen leads to the accumulation of hydrogen at Al3Zr dispersoids and an additional peak in the thermal desorption spectra. For Al18Mg2Cr3 dispersoids, the elastic strain induced by lattice misfit decreases by the introduction of the misfit dislocations leading to hydrogen trapping by misfit dislocations. The obtained results firstly revealed that the presence of coherent Al3Zr dispersoids in the matrix results in a superior hydrogen embrittlement resistance of the alloy.