INFILTRATION AND SOLIDIFICATION REMELTING OF A PURE METAL IN A 2-DIMENSIONAL POROUS PREFORM

Infiltration and solidification/remelting of a pure metal in a two-dim ensional porous preform are modeled numerically. It is assumed that un der the action of constant applied pressure, the flow of liquid metal through the preform is within the range of the validity of Darcy's Law . The distinguishing feature of this flow and hear transfer problem is the existence of two moving fronts: the infiltration front and the re melting front. The governing momentum and energy equations are nondime nsionalized and cast into a Body-Fitted Coordinates (BFC) system to de al with the transient and irregular physical domains. The dimensionles s groups that govern the infiltration and remelting processes are: the dimensionless pressure difference, the dimensionless melting temperat ure, the preform permeability ratio, porosity, and the geometric param eters (inlet gate size, and the preform aspect ratio). A computational code has been developed to solve the problem and is verified by using the available published results. The key parameters describing the ph ysical phenomena, i.e., the infiltration front and remelting front evo lution, the total infiltration rime, and the remelting region size, ar e presented as a function of the operating variables for two different aspect ratios. The results can be used to optimize the infiltration p rocessing of Metal-Matrix Composites and other related manufacturing p rocesses.