Dilute Al–Er-Sc-Zr-Si alloys strengthened by coherent Al₃(Er,Sc,Zr)(L1₂) nanoprecipitates have excellent coarsening- and creep-resistance up to 400 °C. Herein, the effects of micro-additions of 0.25 at.% Mn and/or 0.10 at.% Mo to a dilute Al-0.08Zr-0.014Sc-0.008Er-0.09Si (at.%) alloy are investigated with respect to precipitate evolution and the resulting strengths after different aging treatments. Both Mn and Mo provide solid-solution strengthening, contributing to ambient-temperature strength, in addition to elevated-temperature creep resistance. L1₂-core-shell nanoprecipitates created upon aging at 400 °C exhibit Mn partitioning at the Sc- and Er-rich precipitate cores, and Mo throughout the precipitates. Manganese-modified L1₂-precipitates exhibit a higher number density (~7.5 × 10²² m⁻³ for peak-aged condition), while Mo-modified L1₂-nanoprecipitates display significantly improved coarsening-resistance. No notable synergistic effect of Mn and Mo additions strengthening upon isothermal aging at 400 °C are observed. Isochronal aging displays, however, that a Mo addition delays the formation of Al/Si/Mn-rich α-precipitates from 425 °C to 475 °C. Both Mn and Mo additions improve the creep resistance of the alloys at 300 °C. Manganese-bearing alloys exhibit a more significant effect, as it doubles the threshold stress compared to the Mn-free base alloy. This strong effect could be a result of fine α-precipitates (<20 nm) formed during the creep experiments at 300 °C for the peak-aged sample. The over-aged Mn-containing samples are less creep resistant due to coarsening of both existing L1₂-nanoprecipitates and the absence of fine α-precipitates formed during creep.

由相干的Al ₃（Er，Sc，Zr）（L1 ₂）纳米相强化的稀Al-Er-Sc-Zr-Si合金在400°C时具有出色的抗粗化和抗蠕变性。在本文中，研究了向稀Al-0.08Zr-0.014Sc-0.008Er-0.09Si（at。％）合金中微量添加0.25 at。％Mn和/或0.10 at。％Mo的效果经过不同的时效处理后的演变和强度。Mn和Mo都提供固溶强化，除了提高了耐高温蠕变性外，还有助于提高环境温度强度。在400°C时效时生成的L1 ₂核壳纳米沉淀在富Sc和Er的沉淀核上表现出Mn分配，并且整个沉淀中都含有Mo。锰改性的L1 ₂析出物显示出更高的数密度（峰值时效条件下约为7.5×10 ²²  m ^-3），而Mo改性的L1 ₂-纳米沉淀显示出显着改善的耐粗化性。观察到在400°C等温老化时，Mn和Mo的添加没有明显的协同作用。但是，等时老化表明，添加Mo可以将富Al / Si / Mn的α-沉淀物的形成时间从425°C延迟到475°C。Mn和Mo的添加均可改善合金在300°C时的抗蠕变性。含锰合金显示出更显着的效果，因为与不含Mn的基体合金相比，它使阈值应力增加了一倍。这种强大的影响可能是由于在300°C的蠕变实验中，峰值时效样品形成了细小的α沉淀（<20 nm）。由于两个现有的L1 ₂均变粗，所以过时的含Mn样品的抗蠕变性较差-纳米沉淀，并且在蠕变过程中不形成细的α-沉淀。