EFFECT OF ALLOYING ELEMENTS ON THE SOLIDIFICATION CHARACTERISTICS AND MICROSTRUCTURE OF AL-SI-CU-MG-FE-380 ALLOY

The effect of varying the major alloying elements within the limits of specification on the solidification behavior, fluidity, and microstructure of a 380 alloy has been studied at two cooling rates. The thermal analysis technique has been used to study the solidification behavior. The alloying elements investigated ranged from 3.22 to 4.09 pct copper, 1.01 to 1.70 pct iron, 0.06 to 0.50 pct magnesium, 1.69 to 3.00 pct zinc, and 0.16 to 0.46 pct manganese. The results show that the solidification behavior of the 380 alloys is complicated, and the cooling curve at 0.4-degrees-C/s indicates six reactions taking place during the process of solidification. Cooling curves obtained for each of the alloying element additions, their analysis, and the resultant microstructures are discussed.