Patent ID: 8057855

Claim:
A process for densifying porous structures inside a furnace using nonpressure gradient CVI/CVD, the process comprising: providing a furnace; disposing a number of porous structures in a stack within the furnace, wherein the stack has a center opening region extending through the porous structures and an outer region extending along the outside of the porous structures; providing channels for fluid communication between the center opening region and the outer region; introducing a first portion of a gas composition comprising highly reactive gas to the center opening region; introducing a second portion of the gas composition to the outer region, wherein the first portion and the second portion are controlled proportions thereby introducing predetermined portions of the gas composition to both the center opening region and the outer region; densifying the porous structures from an average density of less than 0.60 g/cm 3 to an average density of greater than 1.70 g/cm 3 in a single cycle of nonpressure gradient CVI/CVD.