Patent ID: 8568838

Claim:
A method for densifying one or more porous articles, comprising: loading the one or more porous articles in a reaction chamber having one or more induction coils and a tuning capacitor; submerging the one or more porous articles and the one or more induction coils in a liquid precursor for a densifying matrix material so that the liquid precursor infiltrates pores in the one or more porous articles; inductively heating the one or more porous articles using the one or more induction coils to a temperature sufficient to cause a vapor layer to form at an interior surface of the pores of the one or more porous articles, and sufficient to cause vapor in the vapor layer to pyrolize and deposit the densifying matrix material within the pores of the one or more porous articles; and controlling a densification kinetic of each of the one or more porous articles, the densification kinetic being weight gain by a porous article per densification time, wherein inductively heating and controlling the densification kinetic of the one or more porous articles comprises matching a resonant frequency of the tuning capacitor with that of the one or more induction coils so as to actively control AC electrical power supplied to drive the one or more induction coils during densification, wherein actively controlling electrical power supplied to drive the one or more induction coils during densification includes periodically changing a resonant frequency variation in the AC electrical power supplied to the one or more induction coils during densification, and changing the resonant frequency variation of the AC electrical power includes: periodically measuring a resonant frequency of the AC electrical power being supplied to the one or more induction coils; calculating a variation in the measured resonant frequencies of the AC electrical power being supplied; comparing a respective calculated resonant frequency variation with a resonant frequency variation set point, the resonant frequency variation set point being a predetermined change in resonant frequency over time; and adjusting the AC electrical power level in accordance with the comparison between the calculated resonant frequency variation and the resonant frequency variation set point.