Ductile and Corrosion-Resistant Aluminum Alloy From Recycled Secondary Aluminum Scraps Containing Iron Impurities

Author(s)

Freitas, Brenda Juliet Martins ; Koga, Guilherme Yuuki ; Mendes, Marcio Andreato Batista ; Kiminami, Claudio Shyinti ; Botta, Walter Jose ; Bolfarini, Claudemiro

• Document type: Journal article
• Source: METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE; v. 54, n. 4, p. 18-pg., 2023-06-05.

Abstract

The alloy was produced by spray forming (SF) of aluminum scraps followed by rotary swaging (RS), and submitted to heat treatments (HT) at 773 K for 15, 30, and 45 hours, resulting in different degrees of globulization and dissolution of Si and theta-Al2Cu particles. The effect of its microstructural features on the electrochemical behavior was assessed by potentiodynamic polarization and electrochemical impedance spectroscopy tests in 0.6 M NaCl solution, and baselined against a conventionally as-cast commercial 319 alloy. Tensile test was also performed to compare the mechanical properties of the alloy in different stages of the processing. Although highly iron contaminated, by using this three-step recycling process, it is possible to achieve an outstanding tensile ductility and the post heat treatment promoted both the relief of the stress concentration and the partial dissolution of the theta-Al2Cu particles, reducing the effect of microgalvanic corrosion and consequently slightly improving the corrosion performance of the alloy. This work thus contributes for the understanding of the effect of microstructures dictated by the heat treatment on the electrochemical corrosion in chloride-rich medium of Al-Si-Cu-Fe alloys processed by SF and RS. These findings regarding the recycling of secondary Al-Si alloys may also open the possibility to replace primary aluminum alloys in structural applications. [GRAPHICS] . (AU)

• FAPESP's process: 19/05885-7 - Microstructure, mechanical properties and corrosion resistance of boron-modified stainless steels processed by additive manufacturing
• Grantee: Brenda Juliet Martins Freitas
• Support Opportunities: Scholarships in Brazil - Doctorate