As-cast microstructure features of Al sheet for manufacturing a pressure can with high formability prepared by different melt-treatment technology were observed by SEM （scanning electron microscope）

EDAX

TEM （transmission electron microscope） and SAED （selected area electron diffraction）. The results reveal that oxide inclusions in the Al sheet are mainly γ-Al2O3 phase

and Fe-rich impurity phases in the Al sheet are mainly Al3Fe

T1（Al12Fe3Si） and AlFeSiRE phase

in which AlFeSiRE phase exhibits complicated non-determined structure. Melt-treatment technologies exhibit remarkable effects on microstructure of as-cast aluminum sheet. There exists much oxide inclusion with large size approximately 10

4

0 μm in diameters

non-uniform distribution is gathered together in the large block form

and Al3Fe phase

and T1 phase as well as a little metastable phase Al6Fe phase exhibits coarse acicular structure or skeleton structure in the conventional treatment or treated-free aluminum sheet

furthermore

the oxide inclusion is easy to aggregate with Fe-rich phases. While in high efficiency melt-treatment aluminum sheet

there exists a little oxide inclusion with uniformly dispersive distribution and fine size less than 4μm

and Re-rich phases are mainly AlFeSiRE phase and little Al3Fe phase

in which AlFeSiRE phase exhibits fine spheroidal structure with size less than 0.5μm or short rod structure distributing along grain. In addition

the absence of phenomenon of Fe-rich phases gathering together with oxide inclusions can be observed.