Microstructure Analysis of AlSi10MgMn Aluminium Cast Alloy

Abstract:

The present study was performed on primary AlSi10MgMn cast alloy to analyze the morphology and composition of complex microstructure of the intermetallic phases. AlSi10MgMn cast alloy is a typical casting alloy used for parts with thin walls and complex geometry. It offers good strength, hardness and dynamic properties and is therefore also used for parts subject to high loading. In this study, several methods were used such as: optical light microscopy (LM) and scanning (SEM) electron microscopy in combination with EDX analysis using standard etched or deep etched sample to identify intermetallic. Alloy was analyzed in as-cast state (rapidly cooled right after casting) and after T6 heat treatment. T6 treatment (solution annealing, quenching and age hardening) improves mechanical properties. The results show that the microstructure of AlSi10MgMn alloy consisted of several phases: α-matrix, eutectic, Fe-rich intermetallic phases (Al₁₅(FeMn)₃Si₂, Al₅FeSi), Mg₂Si, Al₈FeMg₃Si₆ and of other phases in formation. Iron-rich intermetallic phases are well known to be strongly influential on mechanical properties in Al-Si alloys. The most common morphology was the long platelets of Al₅FeSi phase. After heat treatment were observed spheroidisation of eutectic Si, dissolution and fragmentation of Fe-phases.

• Periodical: Materials Science Forum (Volume 782)
• Pages: 365-368
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.782.365
• Online since: April 2014
• Authors: Mária Chalupová, Eva Tillová, Mária Farkašová
• Keywords: Al-Si Cast Alloy, Deep Etching, Heat Treatment, Intermetallic Phase, Microstructure

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