Improved uniformity of densification of ceramic composites through control of the initial preform porosity distribution

Abstract

Densification arising from chemical vapor deposition within a porous preform is modeled as a problem in diffusion and reaction. The effect of reaction rate on the nonuniformity of the final densified composite is explored. The possibility of achieving uniform densification by starting with an initially nonuniform porosity distribution is demonstrated with a simulation model. This model permits one to design a densification process from first principles using a simulation tool that yields results on a timescale far less than that of the processing laboratory.