SEMI-EMPIRICAL MODELING FOR COLUMNAR AND EQUIAXED GROWTH OF ALLOYS

ALICIA E. ARES ,; SERGIO F. GUEIJMAN ,; CARLOS E. SCHVEZOV

JOURNAL OF CRYSTAL GROWTH

Elsevier Science B.V.

Lugar: Sara Burgerhartstraat 25. 1055 KV Amsterdam. Netherlands.; Año: 2002 vol. 241 p. 235 - 240

0022-0248

The columnar and equiaxed growth of low-melting point binary alloys (Pb-Sn) was studied in wide range of concentrations. From the temperature measurements a number of important dynamic parameters were derived, such as cooling rate, profiles, gradients and the position and velocity of liquidus and solidus fronts. These parameters where correlated with the structure-like the length of the columnar grains and sizes of the equiaxed grains. These correlations were used to predict the solidification structure with the aid of a thermal model of solidification. An original feature of the thermal model is the way the latent heat is calculated and released. 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.