Computational Modelling of Microstructure evolution during laser surface remelting

The computational model developed for welding can be modified to obtain heat, momentum and species distribution during laser surface remelting. The thermal parameters thus obtained could be used to perform several microstructure predictions. One such study is to obtain the size distribution of bismuth particles during laser suface remelting of Al-Bi hyper monotectic alloys clad on aluminium substrate. The model involves homogeneous nucleation applicable for immiscible (critical) systems, diffusional growth and collision and coalescence due to convection in the melt pool. The model successfully describes the nature of size distribution (asymmetric, with a tail) and the average size as a function of remelting speed for the case of aluminium-bismuth studied.

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