{"title":"CALPHAD-guided suppression of detrimental Fe-containing phases in secondary aluminum alloys","authors":"Chuan Zhang , Alan A. Luo , Fan Zhang","doi":"10.1016/j.calphad.2025.102830","DOIUrl":null,"url":null,"abstract":"<div><div>Recycling aluminum alloys provides significant economic and environmental advantages, yet the formation of Fe-containing intermetallic phases, particularly the brittle β-AlFeSi phase, in secondary (recycled) aluminum alloys presents challenges to their mechanical and corrosion properties. This study investigates the role of Cr and Mn additions in suppressing these detrimental phases in the Al-Si-Fe system based on CALPHAD modeling and experimental validation. The findings highlight the effectiveness of CALPHAD simulations in accurately predicting as-cast microstructures and sludge formation temperatures for the alloys examined in this study, as well as those reported in the literature. The addition of Cr and Mn promotes the stabilization of the α-Al<sub>15</sub>M<sub>3</sub>Si<sub>2</sub> phase and inhibits the formation of the detrimental β-AlFeSi phase. Furthermore, virtual experiments were carried out to identify optimal compositional and thermal conditions for efficient recycling. A model relating Fe content to optimal Cr and Mn additions for industrial recycling, expressed as <span><math><mrow><mi>w</mi><mrow><mo>(</mo><mrow><mi>F</mi><mi>e</mi></mrow><mo>)</mo></mrow><mo>=</mo><msqrt><mrow><mn>0.9</mn><mo>∗</mo><msup><mrow><mi>w</mi><mrow><mo>(</mo><mrow><mi>M</mi><mi>n</mi></mrow><mo>)</mo></mrow></mrow><mn>2</mn></msup><mo>+</mo><mn>0.4</mn><mo>∗</mo><msup><mrow><mi>w</mi><mrow><mo>(</mo><mrow><mi>C</mi><mi>r</mi></mrow><mo>)</mo></mrow></mrow><mn>2</mn></msup></mrow></msqrt><mo>+</mo><mn>0.4</mn></mrow></math></span> is proposed to guide compositional adjustments. This integrated approach, coupling experimental validation with thermodynamic modeling, highlights the effectiveness of CALPHAD in addressing the Fe impurity challenges and enhancing the sustainability of aluminum alloy recycling.</div></div>","PeriodicalId":9436,"journal":{"name":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","volume":"89 ","pages":"Article 102830"},"PeriodicalIF":1.9000,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Calphad-computer Coupling of Phase Diagrams and Thermochemistry","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0364591625000331","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Recycling aluminum alloys provides significant economic and environmental advantages, yet the formation of Fe-containing intermetallic phases, particularly the brittle β-AlFeSi phase, in secondary (recycled) aluminum alloys presents challenges to their mechanical and corrosion properties. This study investigates the role of Cr and Mn additions in suppressing these detrimental phases in the Al-Si-Fe system based on CALPHAD modeling and experimental validation. The findings highlight the effectiveness of CALPHAD simulations in accurately predicting as-cast microstructures and sludge formation temperatures for the alloys examined in this study, as well as those reported in the literature. The addition of Cr and Mn promotes the stabilization of the α-Al15M3Si2 phase and inhibits the formation of the detrimental β-AlFeSi phase. Furthermore, virtual experiments were carried out to identify optimal compositional and thermal conditions for efficient recycling. A model relating Fe content to optimal Cr and Mn additions for industrial recycling, expressed as is proposed to guide compositional adjustments. This integrated approach, coupling experimental validation with thermodynamic modeling, highlights the effectiveness of CALPHAD in addressing the Fe impurity challenges and enhancing the sustainability of aluminum alloy recycling.
期刊介绍:
The design of industrial processes requires reliable thermodynamic data. CALPHAD (Computer Coupling of Phase Diagrams and Thermochemistry) aims to promote computational thermodynamics through development of models to represent thermodynamic properties for various phases which permit prediction of properties of multicomponent systems from those of binary and ternary subsystems, critical assessment of data and their incorporation into self-consistent databases, development of software to optimize and derive thermodynamic parameters and the development and use of databanks for calculations to improve understanding of various industrial and technological processes. This work is disseminated through the CALPHAD journal and its annual conference.