1235 aluminum alloy slab with thickness of 7.0 mm was directly cast and rolled with electrolytic molten aluminum. The effects of cast-rolling zone lengths on the microstructure and tensile mechanical properties of 1235 aluminum alloy slab at room temperature were investigated by means of optical microscope

scanning electron microscope

energy spectrum analyzer and tensile testing machine. The results indicate that when the length of the cast-rolling zone is 60 mm

the grain size of the slab is coarse with severe central segregation and poor mechanical properties. When the length of the casting rolling zone is 63～67 mm

the grain size of the slab is fine with evenly distribution

and the grain size difference is reduced. The central segregation disappears and the comprehensive mechanical properties are desirable. When the length of the casting and rolling zone is increased to 70 mm

the grain size of the slab becomes coarsened

and the central layer segregation is aggravated

so the mechanical properties are decreased. Energy spectrum analysis demonstrates that the central segregation is mainly Al

2

O

3

FeAlSi and complex compounds adsorbed with other atoms. The reasonable length of cast rolling zone of 1235 aluminum alloy slab is 63～67 mm

where the comprehensive mechanical properties are desirable with the average tensile strength above 108.7 MPa and the average elongation after fracture above 37.7%.