Strengthened solid solution and homogenized eutectic structure of Al-based multi-component alloy via electromagnetic stirring

• Published in: Journal of alloys and compounds Vol. 1002; p. 175537
• Main Authors: Wen, Jinchuan, Cheng, Junhua, Min, Xudong, Huang, Yuanchun, Liu, Yu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.10.2024
• Subjects: Electromagnetic stirring treatment; Macro-segregation; Mechanical properties; Microstructure; Multi-component alloys; Solid solubility; Mechanical properties; Electromagnetic stirring treatment; Macro-segregation; Microstructure; Multi-component alloys; Solid solubility
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2024.175537

Macro-segregation and coarse intermetallic compounds (IMCs) are common problems in lightweight multi-component alloys (MCAs), in this work, electromagnetic stirring treatment (EST) and mixed eutectic strategy were proposed to tune the solidified microstructure of Al-based MCA. For the studied MCA, the positive and negative segregation of solute elements (except for Si) were found both lower than 5 % in the ingot, and the macro-segregation was reduced by approximately 50 % after the EST utilized. Also, the dispersion of the fine eutectic β-Mg2Si phase was significantly promoted by applying EST, specifically, its size at the edge of the ingot was ranged in 2–4 μm. Consequently, the alloy prepared by EST present superior strength-plasticity synergy at room temperature (RT), with the ultimate compressive strength reaching 724 MPa at the edge of the ingot and the strain reaching 15.1 % at the center of the ingot. Moreover, EST was determined enhance the content of solid-solutioned Al atoms in the eutectic β-phase, thus varied its crystal structure and reduced its hardness and Young's modulus, and futher enhanced the deformation coordination between the IMCs and the matrix, thereby improving the mechanical properties of the alloy. This study elaborated the underlying mechanism of microstructural homogeneity regulation, the obtained results could offer guidance for fabricating large-sized Al-based MCAs with excellent mechanical properties. •Compositional segregation suppressed by eutectic structure and electromagnetic stirring.•Electromagnetic stirring increased solid solubility, aggravated lattice distortion, generated a diffusion sluggish effect.•Pre-precipitated Q′-phase and phase boundary distortion both promoted the precipitation of θ'-phase.•The solid solution of Al atoms in β-phase led to the decrease of hardness and Young 's modulus.