【摘要】 Al-Cu-Mg-Ag合金的Sc微合金化具有双刃剑效应，一方面Sc元素会消耗Cu元素形成AlCuSc第二相，降低合金强度，另一方面，其可以促进Ω相原位转变为具有优异耐热性能的V-AlCuSc相，显著提高其服役温度。协同提升合金室温强度以及耐热性能成为含Sc耐热铝合金的关键问题。通过在Al-Cu-Mg-Ag-Sc耐热合金中添加不同含量的Zr，尝试与过量Sc结合形成Al₃（Sc,Zr）颗粒，促进具有优异热稳定性能的Al₃（Sc,Zr）与V-AlCuSc相协同析出，从而提高合金的高温服役性能。拉伸性能测试以及多尺度透射电镜表征结果表明，Zr的加入可以有效地细化晶粒，与Sc结合形成Al₃（Sc,Zr）颗粒促进合金析出相析出，并形成Al₃（Sc,Zr）颗粒与V-AlCuSc相共存的结构，使合金在峰时效和400℃热暴露后均具有更高的强度和塑性。更多还原

【Abstract】 Sc microalloying in Al-Cu-Mg-Ag alloys exhibits a double-edged sword. Sc addition can consume Cu solutes to form AlCuSc secondary phases, reducing the strength of alloys. However, Sc addition can promote the in-situ transformation from Ω phase into V-AlCuSc phase with excellent heat resistance, significantly improving the service temperature. Simultaneously enhancing the room-temperature strength and heat resistance of alloys has become a key problems for Sc-containing heat-resistant aluminum alloys. Various Zr contents were added to Al-Cu-Mg-Ag-Sc alloys, aiming to combine excess Sc with Zr to form Al₃（Sc, Zr） particles, promoting the synergistic precipitation of Al₃（Sc, Zr） particles and V-AlCuSc phases, thus improving the high-temperature service performance of the alloy. Tensile test and multi-scale TEM results indicate that Zr addition can refine the grains, which combines with Sc to generate Al₃（Sc,Zr） particles, facilitating the precipitation of the secondary phases. A coexistence structure of Al₃（Sc,Zr） particles with V-AlCuSc phase is formed, leading to higher strength and plasticity of the alloy under peak ageing and after thermal exposure at 400 ℃.更多还原