SOLIDIFICATION PARAMETERS AND MICRO AND MACROSTRUCTURES DURING DIRECTIONAL SOLIDIFICATION OF ALUMINUM-SILICON ALLOYS.

ALICIA E. ARES,; R. CARAM; CARLOS SCHVEZOV

Faculdade de Engenharia, Ilha Solteira, SP, Brasil

Congreso; 4th International School on Crystal Growth and Advanced Materials”.; 2005

International Union Of crystal growth

The experimental growth of binary alloys (Al-Si) was studied in a wide range of concentrations. From temperature measurements a number of important dynamic parameters were derived, such as cooling rates, profiles, gradients and the position and velocities of liquidus and solidus fronts. These parameters were correlated with the structure like length and wide of columnar grains, size of equiaxed grains and dendrite arm spacing. These correlations were used to predict the solidification struture with the aid of a thermal model solidification. The nucleation and growth of equiaxed grains is assumed to follow the supercooling from the liquidus temperature. The main observation from the model is the high number of equiaxed grains, which compete with the columnar growth in the transition.