Jiang Shengyu, Xu Yuantao, Wang Ruihong, Chen Xinren, Guan Chaoshuai, Peng Yong, Liu Fuzhu, Wang Mingxu, Liu Xu, Zhang Shaoyou, Tian Genqi, Jin Shenbao, Wang Huiyuan, Toda Hiroyuki, Jin Xuejun, Liu Gang, Gault Baptiste, Sun Jun
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, China.
Shanghai Key Laboratory of Materials Laser Processing and Modification, Shanghai Jiao Tong University, Shanghai, China.
Nature. 2025 May;641(8062):358-364. doi: 10.1038/s41586-025-08879-2. Epub 2025 Apr 30.
Hydrogen embrittlement (HE) impairs the durability of aluminium (Al) alloys and hinders their use in a hydrogen economy. Intermetallic compound particles in Al alloys can trap hydrogen and mitigate HE, 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 AlSc nanoprecipitates and in situ formed core-shell Al(Mg, Sc)/AlSc nanophases with high hydrogen-trapping ability. The two-step heat treatment induces heterogeneous nucleation of the Samson-phase Al(Mg, Sc) on the surface of AlSc nanoprecipitates that are only above 10 nm in size. The size dependence is associated with AlSc nanoprecipitate incoherency, which leads to local segregation of magnesium and triggers the formation of Al(Mg, Sc). The tailored distribution of dual nanoprecipitates in our Al-Mg-Sc alloy provides about a 40% increase in strength and nearly five times improved HE resistance compared with the Sc-free alloy, reaching a record tensile uniform elongation in Al alloys charged with H up to 7 ppmw. We apply this strategy to other Al-Mg-based alloys, such as Al-Mg-Ti-Zr, Al-Mg-Cu-Sc and Al-Mg-Zn-Sc alloys. Our work showcases a possible route to increase hydrogen resistance in high-strength Al alloys and could be readily adapted to large-scale industrial production.
氢脆（HE）会降低铝合金的耐久性，并阻碍其在氢能经济中的应用。铝合金中的金属间化合物颗粒可以捕获氢并减轻氢脆，但与传统的强化纳米析出物相比，这些颗粒通常以较低的数密度形成。在此，我们报道了在添加钪的铝镁合金中通过尺寸筛选实现的复合析出，以实现具有高氢捕获能力的细小AlSc纳米析出物和原位形成的核壳Al(Mg, Sc)/AlSc纳米相的高密度分散。两步热处理在尺寸仅大于10 nm的AlSc纳米析出物表面诱导了参孙相Al(Mg, Sc)的异质形核。这种尺寸依赖性与AlSc纳米析出物的非共格性有关，这会导致镁的局部偏析并触发Al(Mg, Sc)的形成。我们的铝镁钪合金中双纳米析出物的定制分布使强度提高了约40%，与无钪合金相比，抗氢脆能力提高了近五倍，在充氢量高达7 ppmw的铝合金中达到了创纪录的拉伸均匀伸长率。我们将这种策略应用于其他铝镁基合金，如Al-Mg-Ti-Zr、Al-Mg-Cu-Sc和Al-Mg-Zn-Sc合金。我们的工作展示了一种提高高强度铝合金抗氢性的可能途径，并且可以很容易地应用于大规模工业生产。
