Niobium matrix composites for high temperature turbine blades, phase 2This program demonstrated the feasibility of fabricating fiber-reinforced MMC (niobium matrix) turbine blades to net shape by chemical vapor infiltration (CVI). A controllable, repeatable niobium infiltration process was developed, and the kinetics of both deposition and infiltration were studied. Several continuous refractory fibers (Nicalon, Nextel 440, FP-Al2O3, HPZ, and tungsten mesh) were investigated as potential reinforcements for strengthening niobium. Thermodynamic and experimental evaluation indicated FP-Al2O3 and tungsten to be the most chemically compatible with niobium, while Nicalon, FP-Al2O3, and tungsten were found to be best with regard to reinforcing capability. Finally, a protective coating for iridium was found to provide substantial oxidation protection to the niobium blade matrix.
Document ID
19940004622
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Heng, Sangvavann (Ultramet Co. Pacoima, CA, United States)
Laferla, Raffaele (Ultramet Co. Pacoima, CA, United States)
Tuffias, Robert H. (Ultramet Co. Pacoima, CA, United States)