Simulation of molten metal through a unidirectional fibrous preform during MMC processing

The injection of molten metal through a fibrous preform is one of the techniques used to manufacture metal matrix composites (MMCs). The flow of liquid metal through a fibrous preform constitutes a moving boundary problem of fluid mechanics in a porous medium. In the present model, the isothermal infiltration process is considered. The numerical algorithm, based on the body-fitted finite element method (FEM), can precisely deal with the transient and irregular physical domains and calculate the flow behavior. Numerical results show that the infiltration pattern is strongly influenced by the nature of the preform. The injection flow rate under constant applied pressure decreases with the infiltration time. The effect of the preform orientation on infiltration pattern is also discussed. Similarity analysis shows that the infiltration time is inversely proportional to the ratio of applied pressure to liquid viscosity for the same type of preform. (C) 2008 Elsevier B.V. All rights reserved.