US 12,304,870 B2
CVI matrix densification process
Ying She, Rocky Hill, CT (US); Nitin Garg, Avon, CT (US); Andrew J. Lazur, La Jolla, CA (US); and Olivier H. Sudre, Glastonbury, CT (US)
Assigned to RTX CORPORATION, Farmington, CT (US)
Filed by RTX Corporation, Farmington, CT (US)
Filed on Jun. 30, 2023, as Appl. No. 18/345,518.
Application 18/345,518 is a continuation of application No. 16/798,016, filed on Feb. 21, 2020, granted, now 11,691,924.
Prior Publication US 2023/0348334 A1, Nov. 2, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. C04B 35/80 (2006.01); C04B 35/628 (2006.01); C23C 16/04 (2006.01); C23C 16/455 (2006.01)
CPC C04B 35/80 (2013.01) [C04B 35/62863 (2013.01); C04B 35/62884 (2013.01); C23C 16/045 (2013.01); C23C 16/45557 (2013.01); C04B 2235/3826 (2013.01); C04B 2235/5244 (2013.01); C04B 2235/5252 (2013.01); C04B 2235/614 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A chemical vapor infiltration method comprising:
flowing ceramic precursors through a preform in a reactor and depositing a matrix material on the preform at a first gas infiltration pressure of the reactor;
increasing the first gas filtration pressure to a second gas infiltration pressure; and
lowering the second gas infiltration pressure to a third gas infiltration pressure which is intermediate to the first and second gas infiltration pressures;
wherein the second gas infiltration pressure is maintained until infiltration gas diffusion rate rather than deposition rate controls matrix densification rate; and
wherein the third gas infiltration pressure maintains matrix densification under reaction control rather than diffusion control.