Structurally complex phase engineering enables hydrogen-tolerant Al alloys

Hydrogen embrittlement (HE) impairs the durability of aluminium (Al) alloys and hinders their use in a hydrogen economy1–3. Intermetallic compound particles in Al alloys can trap hydrogen and mitigate HE4, but these particles usually form in a low number density compared with conventional strengthening nanoprecipitates. Here we report a size-sieved complex precipitation in Sc-added Al–Mg alloys to achieve a high-density dispersion of both fine Al3Sc nanoprecipitates and in situ formed core-shell Al3(Mg, Sc)2/Al3Sc nanophases with high hydrogen-trapping ability. The two-step heat treatment induces heterogeneous nucleation of the Samson-phase Al3(Mg, Sc)2 on the surface of Al3Sc nanoprecipitates that are only…

• NN
  National Natural Science Foundation of China

  Awards: BP2018008, U2330203, U23A6013, BL13W1, 92360301, 52071260
• IJ
  International Joint Laboratory for MicroNano Manufacturing and Measurement Technologies
• HE
  Higher Education Discipline Innovation Project

  Award: BP2018008
• NK
  National Key Research and Development Program of China

  Awards: BP2018008, 2024YFB3714000