TY - GEN
T1 - Formation of the solid layer on the top of molten aluminum
AU - Wiredu Damoah, Lucas Nana
AU - Zhang, Lifeng
AU - Adegboyega, Nathaniel Femi
PY - 2010
Y1 - 2010
N2 - The formation of the top solid layer on the molten aluminum in launders during refining and casting, constituting production loss, were experimentally, thermodynamically and kinetically investigated in the current study. The effects of humidity and composition of the metal on the oxide layer were discussed. The thickness of the top thin oxide layer was only 1 - 5 μm, and the rest of the top layer averaging 350μm were mainly composed of aluminum matrix with MgO clusters, other inclusions and Fe-rich precipitated phases. Two most feasible reactions were determined to be responsible for the formation of the thin oxide layer: (1) the oxidation of molten aluminum by water vapor in humid air and (2) the oxidation of dissolved magnesium by O2. Higher humidity enhanced the oxidation of molten aluminum while lower humidity favored dissolve [Mg] oxidation. Increasing the humidity reduced the thickness of the oxide layer, however, resulted in more hydrogen in the molten metal.
AB - The formation of the top solid layer on the molten aluminum in launders during refining and casting, constituting production loss, were experimentally, thermodynamically and kinetically investigated in the current study. The effects of humidity and composition of the metal on the oxide layer were discussed. The thickness of the top thin oxide layer was only 1 - 5 μm, and the rest of the top layer averaging 350μm were mainly composed of aluminum matrix with MgO clusters, other inclusions and Fe-rich precipitated phases. Two most feasible reactions were determined to be responsible for the formation of the thin oxide layer: (1) the oxidation of molten aluminum by water vapor in humid air and (2) the oxidation of dissolved magnesium by O2. Higher humidity enhanced the oxidation of molten aluminum while lower humidity favored dissolve [Mg] oxidation. Increasing the humidity reduced the thickness of the oxide layer, however, resulted in more hydrogen in the molten metal.
KW - Aluminum
KW - Humidity
KW - Magnesium
KW - Oxides
KW - Top Layer
UR - http://www.scopus.com/inward/record.url?scp=77952414568&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:77952414568
SN - 9780873397476
T3 - TMS Light Metals
SP - 773
EP - 778
BT - Light Metals 2010 - Proceedings of the Technical Sessions Presented by the TMS Aluminum Committee at the TMS 2010 Annual Meeting and Exhibition
T2 - Light Metals 2010 - TMS 2010 Annual Meeting and Exhibition
Y2 - 14 February 2010 through 18 February 2010
ER -