Al-Mn alloys with different Mn contents（1.4%、1.7%、2.0%、2.3%

mass fraction）were prepared by permanent mould casting. The microstructure

mechanical properties and anodic oxidation properties of the alloy ingots were characterized by SEM

EDS and tensile testing. The results show that the second phase in Al-Mn alloy consists largely of Al

6

Mn with large diamond shape

long strip shape

spherical shape or short rod shape. The fluidity of the alloy is increased firstly and then decreased. When Mn content is 2.0%

the alloy shows the satisfied fluidity

which is up to 97% of ADC12 alloy at the same level. The strength of alloy is increased firstly and then decreased

while the elongation is decreased continuously. When Mn content is 1.7%

the comprehensive mechanical properties and anodizing properties can be obtained with the desirable effects. The alloy presents great anodizing performance with the color difference less than 0.5

and the thickness of anodic oxide film is more than 10 μm.