M. Gremaud et al., INFLUENCE OF CRYSTALLOGRAPHIC AND HEAT-FLOW ORIENTATIONS ON GROWTH OFCELLULAR DENDRITES, ISIJ international, 33(9), 1993, pp. 941-948
A numerical program has been developed in order to calculate the time-
dependent thermal gradient and isotherm velocity within a solidifying
pool obtained by stationary laser treatment. The heat diffusion equati
on is solved for an axisymmetric geometry with an enthalpy formulation
using a standard FDM implicit scheme. The program has been used to in
vestigate to which extent the cellular dendritic growth orientation is
affected by the direction and amplitude of the thermal gradient. Expe
riments were carried out on Al-1 mass%Si dendritic single crystals ori
ented by Laue back reflection technique and cut along precise crystall
ographic orientations prior to laser irradiation and on Al-33mass%Cu e
utectic polycrystalline alloys. Deviation of cellular dendritic growth
direction from crystallographic and heat flux directions are reported
. In addition, the comparison of the microstructural spacings with the
oretical predictions outlines the influence of crystallography on the
microstructural development during stationary laser treatment.