The Failure Degradation of Recycled Aluminium Alloys with High Content of β-Al₅FeSi Intermetallic Phases

Abstract:

In this study, the effect of the β-Al₅FeSi phases on fracture surfaces in secondary AlSi7Mg0.3 cast alloys with common and higher amount of iron was investigated. Iron addition caused the formation of different Fe-rich intermetallic phases in aluminium alloys. Components made of secondary aluminium alloys commonly have a higher amount of such phases. Sharp needles as β-Al₅FeSi phase lead to initiate stress tension, thereby contributing to increased risk of micro-cracks formation on the fracture surfaces. To determine the effect of β-Al₅FeSi to fracture surfaces of AlSi7Mg0.3 cast alloy, SEM microscopy with energy-dispersive X-ray spectroscopy (EDX) was used to study the amount of needles phases, their morphology and violation wave. It was found that increasing Fe content increased the size and the number of Al₅FeSi phases. The fractographic analysis of fracture surfaces shows an increasing amount of cleavage fracture in materials with a higher amount of iron, too.

• Periodical: Defect and Diffusion Forum (Volume 403)
• Pages: 97-102
• DOI: https://doi.org/10.4028/www.scientific.net/DDF.403.97
• Online since: September 2020
• Authors: Denisa Medvecká*, Lenka Kuchariková, Milan Uhríčik
• Keywords: Aluminium Alloys, Fractographic Analysis, Fracture Surfaces, β-Al₅FeSi Phase

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