Thermodynamics of Formation of Al6Mn Inter-Metallic Compound for Mn Removal from Molten Al–Mg Alloy
Year: 2023
Type: article
Abstract: To reduce CO2 emission, recycling Al scrap into wrought alloy is desired. However, impurity elements are inevitably contained in the Al scrap recovered from the society, and most of them are difficult to be removed by the current pyro-metallurgical processes. Mn is one of the major alloying elements of Al alloys and steels and is contained in Al scraps. Therefore, a removal method of Mn from Al is necessary. Mn easily forms an inter-metallic compound with Al; on the other hand, it is immiscible with Mg in the liquid state, which suggests that the repulsive interaction between Mg and Mn in molten Al enhances the precipitation of intermetallic compounds such as Al6Mn. This study proposed Mn removal from molten Al–Mg alloy through precipitation of Al6Mn inter-metallic compound. Molten Al–Mg alloy was equilibrated with Al6Mn, and the reducing limit of Mn concentration was thermodynamically discussed. Mn concentration becomes lower at higher Mg content of molten Al and lower temperature. The activity coefficient of Mn in molten Al–Mg alloy was increased with the addition of Mg, and the following equation was obtained as a function of temperature and molar fraction of Mg:
Source: MATERIALS TRANSACTIONS
Institutions: University of Toyama, Kobe Steel (Japan)
Language: English
Subfield: Metals and Alloys
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W4317860938