Abstract
During remelting of aluminum manganese-containing alloys, some industrial experience has indicated a tendency toward increased oxidation losses when compared to unalloyed Al. A goal of this work is to increase current knowledge of oxidation of Mn-containing aluminum. An oxidation study was performed on 99.99% Al, Al-1%Mn and Al-5%Mn materials in a muffle furnace in air. These oxidized materials were analyzed in the Scanning Electron Microscope using Energy Dispersive x-ray Spectroscopy (EDS) both for chemical composition and to analyze the structure of the oxide that was formed.
The main findings from the SEM analysis of the oxidized 99.99% Al, Al1%Mn and
Al5%Mn materials are:
1) The oxides formed on the Al1Mn and Al5Mn materials contained only minute amounts of Mn. However, small clusters of Mn metal were found among the Al2O3 particles on the surface of the Al1Mn and Al5Mn samples.
2) Dissolved Mn increased from the surface to the interior, and Mn-rich particles were present in the interior of the Al1Mn and Al5Mn samples.
3) The oxide layer thickness increases with Mn content, and the oxide film is more fragmented.
The main findings from the SEM analysis of the oxidized 99.99% Al, Al1%Mn and
Al5%Mn materials are:
1) The oxides formed on the Al1Mn and Al5Mn materials contained only minute amounts of Mn. However, small clusters of Mn metal were found among the Al2O3 particles on the surface of the Al1Mn and Al5Mn samples.
2) Dissolved Mn increased from the surface to the interior, and Mn-rich particles were present in the interior of the Al1Mn and Al5Mn samples.
3) The oxide layer thickness increases with Mn content, and the oxide film is more fragmented.
