Achieving strength-ductility synergy in novel heterogeneous lamella structures of Al-Mg-Sc-Zr-Ag alloys

This paper presents a novel method for preparing heterogeneously structured AlMgScZrAg alloys with excellent properties by microalloying. The addition of Ag modified the precipitation behavior of the alloy, resulting in the combination of multi-scale precipitates and a heterogeneous lamella structure (HLS). Compared with the alloy without Ag, the AlMgScZrAg alloy exhibited a 29.5% increase in yield strength (from 186 MPa to 241 MPa) without sacrificing plasticity. The synergistic strengthening mechanisms of the ‘heterostructure-dislocation-precipitate’ microstructure enhance both the strength and plasticity.本文报道了一种通过微合金化制备综合性能优异的异质结构AlMgScZrAg合金的新型方法。银元素的添加调控了该合金的析出行为，促使多尺度析出相与异质层片结构（Heterogeneous Lamella Structure，HLS）复合共存。与未添加银元素的合金相比，AlMgScZrAg合金的屈服强度提升了29.5%（从186 MPa升至241 MPa），且未牺牲其塑性。“异质结构-位错-析出相”微观结构的协同强化机制，可同时提升合金的强度与塑性。