Horizontally Solidified Al-3wt%Cu-(0.5wt%Mg) Alloys: Tailoring Thermal Parameters, Microstructure, Microhardness, and Corrosion Behavior

Author(s)

Barros, Andre ^[1] ; Cruz, Clarissa ^[2] ; Silva, Adrina P. ^[1] ; Cheung, Noe ^[2] ; Garcia, Amauri ^[2] ; Rocha, Otavio ^{[1, 3]} ; Moreira, Antonio ^[1]

Affiliation

^[1] Fed Univ UFPA, Inst Technol, BR-66075110 Belem, PA - Brazil

^[2] Univ Estadual Campinas, UNICAMP, Dept Mfg & Mat Engn, BR-13083860 Campinas, SP - Brazil

^[3] Fed Inst Educ Sci & Technol Pard IFPA, BR-66093020 Belem, PA - Brazil

• Document type: Journal article
• Source: ACTA METALLURGICA SINICA-ENGLISH LETTERS; v. 32, n. 6, p. 695-709, JUN 2019.
• Web of Science Citations: 1

Abstract

In the present experimental investigation, Al-3wt%Cu and Al-3wt%Cu-0.5wt%Mg alloys castings are produced by a horizontal solidification technique with a view to examining the interrelationship among growth rate (G(R)), cooling rate (C-R), secondary dendrite arm spacing ((2)), Vickers microhardness (HV), and corrosion behavior in a 0.5M NaCl solution. The intermetallic phases of the as-solidified microstructures, that is, -Al2Cu, S-Al2CuMg, and -Al7Cu2Fe, are subjected to a comprehensive characterization by using calculations provided by computational thermodynamics software, optical microscopy, and scanning electron microscopy/energy-dispersive spectroscopy. Moreover, electrochemical impedance spectroscopy and potentiodynamic polarization tests have been applied to analyze the corrosion performance of samples of both alloys castings. Hall-Petch-type equations are proposed to represent the HV dependence on (2). It is shown that the addition of Mg to the Al-Cu alloy has led to a considerable increase in HV; however, the Al-Cu binary alloy is shown to have lower corrosion current density (i(corr)) as well as higher polarization resistance as compared to the corresponding results of the Al-Cu-Mg ternary alloy. (AU)

• FAPESP's process: 17/16058-9 - Solidification Microstructures and Wear Resistance of Zn-Al-Bi Monotectic Alloys
• Grantee: Noe Cheung
• Support Opportunities: Scholarships abroad - Research