The Microstructural Evolution of AA6111 Aluminum Alloy during Homogenization Treatment

Abstract:

The microstructures of AA6111 automotive aluminum alloy were investigated by optical microscopy (OM), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), differential scanning calorimetry (DSC), X-ray diffraction analysis (XRD) and transmission electron microscope (TEM). The results indicated that as-cast AA6111 alloy has a complex microstructure. There were many kinds of intermetallic phases, such as lath-shaped β-Al₅FeSi, Al₁₅(FeMn)₃Si₂ and Mg₂Si on the grain boundaries. The Al₅Cu₂Mg₈Si₆ precipitates presented non-equilibrium eutectic morphology in the grain interiors. After homogenization treatment (6h at 470), the low melting point Mg₂Si phase began dissolving. The eutectic Al₅Cu₂Mg₈Si₆ phase were dissolved completely after 530/24h homogenization treatment. The Al₁₅(FeMn)₃Si₂ phase started to be spheroidized at 560. Increasing treatment temperature will promote Mn to substitute for Fe in this phase.

• Periodical: Materials Science Forum (Volume 749)
• Pages: 223-228
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.749.223
• Online since: March 2013
• Authors: Shi Jiao Zhang, Bai Qing Xiong, Yong An Zhang, Xi Wu Li, Feng Wang, Zhi Hui Li, Hong Wei Liu
• Keywords: 6111 Aluminum Alloy, Homogenization Treatment, Microstructure

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