Numerical analysis of solidification process for matrix alloys in continuous fiber reinforced composites

A 2-dimensional numerical simulation was applied to evaluate the thermal and solutal influences of fibers on the dendrite growth of matrix alloy reinforced with continuous fibers. The Cellular Automaton model and direct finite difference method with a rectangular grid are used for calculation. The results of temperature and solute distribution, and dendrite tip undercooling and tip radius were compared with experimental data for fiber reinforced succinonitrile-acetone alloy. In the experimental results, the gap of dendrite tips between the composite and bulk regions increased as the fiber interstices became smaller, indicating the tip undercooling was increased in the fiber spacing. Furthermore, the dendrite tip radius decreased with decreasing the fiber interstices. In addition to the changes of these parameters, the growth of the secondary dendrite arms was constrained and almost stopped by the presence of the fibers. Numerical analysis revealed that the presence of fibers can cause an increase of solute pile up and a change of dendrite morphology, when the fiber interstice becomes smaller than the primary dendrite arm spacing.