Liquid/solid (L-S) interface migration during transient liquid phase bonding of Ni-Ni with Ni-11 mass% P filler metal was simulated by using a two dimensional finite difference model. Two problems were numerically solved. First, non flat L-S interface migration behavior during dissolution of Ni base metal was analyzed. Second, grain boundary grooving behavior was analyzed. It was found that grain boundary grooving due to energy balance between L-S interface and grain boundary is produced when the grain boundary diffusion is nearly equal to the volume diffusion within the base metal. On the other hand, the abnormal deep channel-like grain boundary grooving, which is not explained by the energy balance, is produced by a small decrement of P content C_(LG) at the intersection of the grain boundary with the L-S interface (triple point), i.e., by a small decrease of the liquidus (melting) temperature at the triple point.
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