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: NORTH-HOLLAND; 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 a wide range of concentrations. From temperature measurements a number of important dynamic parameters were derived, such as cooling rates, profiles, gradients andthe position andvelocity of liquidus andsolid us fronts. These parameters were correlatedwith the structure-like length of columnar grains andsize of equiaxedgrains. These correlations were usedto 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 equiaxedgrains, which compete with the columnar growth in the transition. r 2002 Publishedby Elsevier Science B.V.r 2002 Publishedby Elsevier Science B.V.