Effect of Pouring Temperature on Fe-Containing Phase in Microstructure of A380 Cast Aluminum Alloy

The A380 cast aluminum alloy is widely used in the cylinder block, cylinder head and piston of automobile due to its excellent wear resistance and corrosion resistance, low thermal expansion coefficient and high strength-to-mass ratio. The pouring temperature is an important process parameter for A380 alloy to obtain excellent mechanical properties.The evolution of Fe-containing phase in the microstructure of A380 aluminum alloy (Fe=1.1wt%) was studied at different pouring temperatures of 700-900℃. The results show that the precipitation of the harmful β-Fe phase in the alloy is almost suppressed when the pouring temperature is above 800℃. With the increase of pouring temperature, the secondary dendrite arm spacing of the A380 alloy gradually decreases when the pouring temperature is ranging from 700℃to 900℃, the hardness of A380 alloy is generally increased, which corresponds to the content and proportion of α-Fe phase and β-Fe phase in the microstructure.