Numerical modeling of solidification morphologies and segregation patterns in cast dendritic alloys

✍ Scribed by L. Nastac

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 341 KB
• Volume: 47
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/s1359-6454(99)00325-0

✦ Synopsis

AbstractÐA comprehensive stochastic model for simulating the evolution of dendritic crystals during the solidi®cation of binary alloys was developed. The model includes time-dependent calculations for temperature distribution, solute redistribution in the liquid and solid phases, curvature, and growth anisotropy without further assumptions on the nucleation and growth of dendritic crystals. Stochastic procedures previously developed by Nastac and Stefanescu (Modell. Simul. Mater. Sci. Engng, 1997, 5(4), 391) for simulating dendritic grains were used to control the nucleation and growth of dendrites. A numerical algorithm based on an Eulerian±Lagrangian approach was developed to explicitly track the sharp solid/liquid (S/L) interface on a ®xed Cartesian grid. Two-dimensional mesoscopic calculations (i.e. at the dendrite tip length scale) were performed to simulate the evolution of columnar and equiaxed dendritic morphologies including the formation of the columnar-to-equiaxed transition. The eects of solutal and curvature undercoolings on the evolution of both the dendrite morphology and segregation patterns during the solidi®cation of binary alloys were analyzed in detail.