Impregnation Molding of Particle‐Filled Preceramic Polymers: Process Modeling

A process model is presented for the analysis and simulation of impregnation molding of particle‐filled, continuous‐fiber ceramic composites. A multidimensional, transient particle filtration formulation is coupled with isothermal, anisotropic Darcy flow to predict filler‐concentration profiles during molding. The particle filtration is insensitive to the injection flow rate; however, in irregularly shaped molds, the geometry of the mold greatly influences the local velocities, which results in local variations in the rate of filtration. Although the preform volume fraction and inlet particle concentration influence the particle accumulation quantitatively, the filtration coefficient and the permeability have a dominant role in setting the filtration trend.