Numerical simulation of the pressure infiltration of fibrous preforms during MMC processing

Abstract

In the pressure infiltration process of metal-matrix composites, molten metal is injected under external pressure into a porous preform of the reinforcing phase and solidified, either during infiltration or after the mold is filled. To simplify the problem, the assumption of isothermally saturated fibrous preform with molten metal is adopted. The flow of molten metal is a moving boundary phenomenon which is similar to a fluid flowing through a porous medium. A numerical technique, body-fitted finite element method (FEM), is used to generate grids inside the physical domain and to calculate the distribution of pressure and other relative properties. Results show that the injection flow rate exponentially decreases with the infiltration time. Increasing injection pressure can effectively reduce the infiltration time. A simple and practical prediction of infiltration time under the various parameters is also provided in this study.

Keywords:

• METAL MATRIX COMPOSITE
• INFILTRATION PROCESS
• BODY-FITTED FINITE ELEMENT METHOD