High strength-ductility synergy induced by sub-rapid solidification in twin-roll cast Al–Mg–Si alloys

• DOI: 10.1016/j.jmrt.2021.12.055
• Publication Date: 2021-12-16T18:10:16Z
• Authors: Shao-You Zhang; Xuan Wang; Xu Liu; Yuan-Ting Mo; Cheng Wang; Tuo Cheng; Orest Ivasishin; Hui-Yuan Wang
• Keywords: Ingot; Ductility (Earth science); Volume fraction; Elongation; Supersaturation; Solid solubility; Precipitation hardening; Hardening (computing)

Regulating the morphology and composition of Fe-containing phases can significantly improve mechanical properties Al–Mg–Si alloys. Here, we successfully prepared high-performance AA6061 alloys by route sub-rapid solidification (SRS) based on twin-roll casting (TRC). Excellent tensile strength (∼372 MPa) elongation (∼19%) were achieved in peak-aged TRC sample, which increased simultaneously compared with counterpart (∼351 MPa ∼14%) fabricated via ingot (IC). It was found that strength-ductility synergy sample caused high cooling rate, wherein SRS refine microstructure promote reaction from AlFeSi to AlFeMgSi (Mg:Fe:Si = 1:1.5:2.5) phase. The centerline segregation strip could be well mitigated during solution treatment because reduced size Mg-incorporation accelerated redissolution phases. alleviative greatly promoted supersaturated solution, thus contributing ductility. Meanwhile, Si-rich phase decompose into Fe-rich α-AlFeSi (Fe:Si > 1) treatment, expanded solid solubility Si Mg. Therefore, an enhanced aging hardening response obtained showing number density volume fraction β” results would provide guidelines for developing TRC.